Unit 09 Industry and occupation awareness By Chelsea Welton.
WHAT IS THE RELATIONSHIP BETWEEN INDUSTRY, OCCUPATION, AND ... · WHAT IS THE RELATIONSHIP BETWEEN...
Transcript of WHAT IS THE RELATIONSHIP BETWEEN INDUSTRY, OCCUPATION, AND ... · WHAT IS THE RELATIONSHIP BETWEEN...
WHAT IS THE RELATIONSHIP BETWEEN INDUSTRY,
OCCUPATION, AND BODY WEIGHT IN CANADA?
by
Saibiao Peng
Bachelor of Economics, Hunan Normal University, 2011
A Report Submitted in Partial Fulfilment of Requirements for the Degree of Master of Arts
In the Graduate Academic Unit of Economics
Supervisor: Philip Leonard, PhD, Dept. of Economics
Examining Board: Weiqiu Yu, PhD, Dept, of Economics
Paul Peters, PhD, Dept, of Economics
This report is accepted by the Dean of Graduate Studies
THE UNIVERSITY OF NEW BRUNSWICK
January, 2017
©Saibiao Peng, 2017
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Abstract Overweight and obesity are well known to be associated with negative health
outcome. Canadians spend a large portion of their walking hours at work and their
level of physical activity (or lack thereof) and eating habits while there likely play a
role in their body weight. This study examines the association between industry and
occupation of work and the likelihood of overweight and obesity. This paper
managed to discover social economic factors and human behavior factors that will
help identify groups that are most at risk of being overweight and obese. Cycle 5 of
NPHS and all 8 cycles of CCHS are used in logit and fixed-effect models to run
regression analysis. Results show that compare to male, female are less likely to
become overweight and obese, age has negative effect on people’s body weight, and
people who live in Ontario, Birth Columbia have the lowest risk of being overweight
and obese. Also the results indicate that the following variables: education,
household-income, physical activity and eating habits are negatively associated with
being overweight and obese. For industry and occupation, the results show: people
who work at public administration and education industry have highest risk to
become obese; Occupation as manager or sales contribute most to people’s risk of
being obese.
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Acknowledgement
First of all, I need to extend my sincere gratitude to my supervisor, professor Philip
Leonard, with his patiently encouragement and guidance. And without his support I
could not complete this report and reached its present form. Also, I need to thanks
for professor Weiqiu Yu and professor Paul Peters, thanks for their useful comments
and suggestions on my report.
At last, I need to gratitude my parents and friends, thanks for their support and
encourage.
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TABLE OF CONTENTS
Abstract………………………………………………. ii
Acknowledgment………………………………. iii
Table of Contents ………………………………. iv
List of Tables ……………………………………… v
I Introduction …………………………………... 1
II Literature Review …………………………….. 3
2.1 Measurements ………..………………………….. 3
2.2 Prevalence ………………………….…………..... 5
2.3 Effects ……………………………………………. 7
2.4 Potential explanations for Obesity ……………. 10
III Models and data …………..……………………………....... 16
IV Results ……………………………………..... 33
4.1 CCHS Results ……………………………………….. 33
4.2 NPHS Results ……………………………………….. 38
4.3 NPHS Longitudinal Results ………………………… 42
4.4 Link-test ………………………………………….. 44
V Discussion …………………………………….... 45
VI Conclusion ……………………………………………………. 51
References ……………………………………………………….. 89
Appendix ……………………………………………. 93
Curriculum Vitae
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List of Tables Table 1: Health risk classification according to Body Mass Index…………...3
Table 2: Ethnic-specific values for waist circumference promoted by the WHO and
Canadian Diabetes Association………………………………………………..4
Table 3: Adults who are obese in 2014 by province to territory in Canada…...7
Table 4: Logit model based on overweight as outcome (CCHS, 2007-2014)…55
Table 5: Logit model based on obesity as outcome (CCHS, 2007-2014)……..61
Table 6: Logit model based on overweight as outcome (NPHS, cycle 5)……..67
Table 7: Logit model based on obesity as outcome (NPHS, cycle 5)……….....73
Table 8: Fixed effect logit model based on overweight as outcome (NPHS)….83
Table 9: Fixed effect logit model based on obesity as outcome (NPHS)………62
Table 10: Rank of industry and work occupation based on BMI (for
overweight)…………………………………………………………...50
Table 11: Rank of industry and work occupation based on BMI (for obesity) ….50
Table 12: 4 groups of work occupation category……………………………….93
Table 13: 9 groups of industry category…………………………………………93
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List of figures
Figure 1: Percentage of who were overweight or obesity (self-report), by sex,
household population aged 18 and older, Canada, 2003 to 2014, percent……….7
Figure 2: Relationship between BMI and highest level of education (CCHS)…..22
Figure 3: Relationship between BMI and household income (CCHS)…………..23
Figure 4: Relationship between BMI and work occupation (CCHS)…………….24
Figure 5: Relationship between BMI and 9 groups of industries (CCHS)……….24
Figure 6: Relationship between BMI and highest level of education (Cycle 5,
NPHS)…………………………………………………………………………….25
Figure 7: Relationship between BMI and household income (Cycle 5, NPHS)….25
Figure 8: Relationship between BMI and work occupation (Cycle 5, NPHS)…..26
Figure 9: Relationship between BMI and industry (Cycle 5, NPHS)…………….27
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I Introduction:
According to the World Health Organization (WHO), the global obesity rate more
than doubled between 1980 and 2014. More than 1.9 billion adults (18+)were
overweight, and more than 600 million people were obese in 2014 (WHO, 2016). The
World Health Organization has defined obesity as abnormal or excessive fat
accumulation that may impair health, and described the main reason leading to
overweight and obesity as an energy imbalance between calories consumed and
calories expended (WHO, 2010). Much research has proven that high body mass
index (BMI) is a major risk factor for non-communicable diseases like: cardiovascular
diseases, musculoskeletal disorders and some cancers (Akil & Ahmad, 2011).
Moreover, Hammond and Levine (2010) have done research from four perspectives:
direct medical costs, productivity costs, transportation costs, and human capital costs
to find the relationship between economic impacts and obesity. They found that
people in United States have annual economic costs associated with obesity in excess
of $215 billion (Hammond & Levine, 2010).
There are many papers that have analyzed the specific causes of high body mass
index. Kelly et al. (2012) tried to study the impact of early occupational choice on
health behaviors, by using the American Time Use Survey (ATUS) by following
Grossman’s health demand model. Their findings suggested that initial occupations
described as craft, operative, and service are related to high body mass index and
obesity later in life. People who work in those industries/occupations have higher
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physical activity involved. One of my critical hypotheses is, as higher body activities
are required in their job, people’s risk of being obese will be greater. Inas and Dhaval
(2012) found that initial blue-collar work is associated with a higher probability of
being obese. Even though physical activity has a positive relationship with health, this
relationship could be explained better by the contribution of leisure physical activities,
other than work-based physical activities. Meanwhile, work stress will influence
people’s body weight in many ways. A recent study by Isabel Diana Fernandez found
that people who were left behind at a downsized company often carry more stress and
higher body weight. That study supports another hypothesis of mine, that the heavier
the stress workers are carrying, the higher the risk for them to become obese. Chaput
et al. (2015) conducted a longitudinal analysis from the Quebec Family Study
(Canada) to estimate the relationship between workplace standing time and the
incidence of obesity and type 2 diabetes. According to their research, long
occupational standing time is not sufficient in and of itself to prevent overweight and
obesity in adults. However, there are limited studies that examined in the relationship
between specific industries, work occupations, and overweight/obesity in Canada.
Therefore, this report will focus on which industries and work occupations are most at
risk of being overweight and obese.
Based on the Canadian Community Health Survey (CCHS) and Canada’s
National Population Health Survey (NPHS), I will use basic logit models and
fixed-effect logit models to identify which industries and work-occupations are
associated with the highest risk of being overweight and obese. Also, household
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income, education and lifestyle factors have been tested to find whether these
variables could lead to greater probability of being overweight and obese.
The rest of the report is organized as follows: SectionⅡreviews the literature and
introduces the measurement of adults’ obesity, the prevalence of overweight and
obesity in Canada, the effects and causes of overweight and obesity. Section Ⅲ
describes the methodology and variables. Then, in Section Ⅳ, I will show the
relationship between education, household income, work occupation, industry, and the
categories of body mass index (BMI), graphically. Also in this section, I will describe
the data from two surveys. Finally, I will show the results and the conclusion in last
two sections of my paper.
II Literature review
2.1 Measurement:
There are three major ways to measure an adult’s individual obesity; the first one is
BMI defined as the human’s weight in kilograms over the square of the height in
meters; a BMI over 30 is defined as obese and over 25 is defined as overweight.
BMI and health risk have different classifications in various countries, Table 1 show
the BMI classification by WHO and Health Canada.
Table 1: Health Risk Classification according to Body Mass Index (BMI)
Classification BMI Category (kg/𝑚2) Risk of Developing Health
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Problem
Underweight < 18.5 Increased Risk
Normal Weight 18.5- 24.9 Least Risk
Overweight 25.0- 29.9 Increased Risk
Obese Class I 30.0- 34.9 High Risk
Obese Class II 35.0- 39.0 Very High Risk
Obese Class III >= 40.0 Extremely High Risk
Note 1: For persons 65 years and older the ‘normal’ range may begin slightly above BMI 18.5 and
extend into the ‘overweight’ range.
Note 2: For use with adults over the age of 18, excluding pregnant and lactating women.
The second classification is Waist Circumference (WC) which is an indicator of
health risk associated with excess fat around the waist. The World Health
Organizations recommended measurement method is to let participants stand, feet
apart from 25 to 30 cm, weight evenly distributed. Measurement location is the in
horizontal edge of a former iliac crest and the 12th ribs on the halfway point of the
attachment. Measuring scale should be close to the soft tissue, but cannot oppress
those tissues. Measuring accuracy value to 0.1 cm (WHO.2013). Table 2 shows values
of waist circumference standards below.
Table 2: Ethnic-specific Values for waist circumference promoted by the WHO
and Canadian Diabetes Association.
Country or ethnic group Central obesity as defined by
WC
5
Men- cm
(inches)
Women-cm
(inches)
European, Sub-Saharan African, Eastern
Mediterranean and Middle Eastern (Arab)
94(37.6) or
greater
80(32) or
greater
South Asian, Chinese, Japanese, South and Central
American
90(36) or
greater
80(32) or
greater
Note: For use with adults over the age of 18, excluding pregnant and lactating women.
The obesity standards for men are different between Western Countries and Eastern Countries;
there are 94cm and 90cm respectively. However, the overweight standards for women are the
same cross world. Once the WC is over 80cm, women can be defined as obese.
The third way is called Waist Hip Ratio (WHR). According to Wikipedia, the World
Health Organization’s data gathering protocol, WHR, is the ratio of waist
circumference to hip circumference. Hip circumference is the most outstanding points
around the hip measuring the circumference of the body level. By using waist
circumference over hip circumference, the measurement of obesity for white male is
greater than 0.90 and for white female is greater than 0.85(WHO, 2008). WHR tests
the level of abdominal and adipose accumulation.
For this study I will use National Population Health Survey and Canadian
Community Health Survey, which are collected by Statistics Canada. These surveys
include individuals’ measured height and weight, which are the required variables to
estimate BMI. There are several studies that use Body Mass Index to estimate the
relationship between obesity, insufficient physical activity and household income
level. For example, Jolliffe (2011) studied the relationship between income and body
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mass index by using the National Health and Nutrition Examination Survey
(NHANES). After using the unconditional quantile regression to analyzed the
differences between poor and non-poor, male and female, he found that there is a
significant relationship between BMI and income level. Moreover, increased income
will reduce the BMI value. Petersen et al. (2016) studied the relationship between
sitting time for non-strenuous workers and their BMI. He used time analysis to prove
that among workers in non-strenuous jobs, every 10 additional hours spent on
working will be associated with an increase in BMI of 0.424 for women and 0.197 for
men, representing an increase of 2.5 and 1.4 pounds, respectively. According to WHO
Diabetes Country Profiles 2016, BMI is related to blood pressure diseases and cancer.
Since only BMI is available in the NPHS and CCHS, Waist Circumference and Waist
Hip Ratio will not be considered in this study. As per the standard for Canada, I use a
BMI cutoff of 30 for obesity and 25 for overweight in all of my analysis.
2.2 Prevalence:
According to Canadian Community Health Survey, the trend of obese adults among
the population is smoothly but steadily increasing from 2003-2014. Obesity rates were
16% for adult men and 14.5% for adult women in 2003; those rates become 21.8%
and 18.7% respectively in 2014. This significant change might be due to
self-reporting bias, since changes of obesity rate should be small during short term
cycle. CCHS is a cross-section survey that collects information related to health status,
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health care utilization and health determinants for the Canadian population. There
were approximately 130,000 respondents interviewed during the reference periods of
2001, 2003 and 2005; the sample size decreased 65,000 each year since 2007 as the
survey were conducted annually instead of bi-annually. There are therefore gaps in
2004 and 2006, in which no data are available. Figure 1 shows
Figure 1, Percentage of respondents were overweight or obese (self-report), by
sex, household population aged 18 and older, Canada, 2003 to 2014.
Sources: Canada Community Health Survey, overweight and obese adults 2003, 2005, 2007 to
2014.
Based on CCHS 2014, there are regional differences among provinces. As Table 3
shows, compared to the national average, Newfoundland and Labrador, Nova Scotia,
New Brunswick, and Northwest Territories have significantly higher obesity rates
(10.2%, 7.6%, and 6.2% 13.2% respectively). On the other hand, British Columbia
and Quebec have significantly lower obesity rates (4.25% and 2% respectively) than
the national average of 20.2%. Ontario has similar obesity rate as the national
average.
Table 3: Adults who are obese in 2014 by province to territory in Canada:
0
10
20
30
40
50
2003 2005 2007 2008 2009 2010 2011 2012 2013 2014
Overweight men
Overweight women
Obesity men
Obesity women
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Province or territory Prevalence (%)
National 20.2
Prince Edward Island 24.2
Newfound and Labrador 30.4
Nova Scotia 27.8
New Brunswick 26.4
Quebec 18.2
Ontario 20.4
Manitoba 24.5
Saskatchewan 25.1
British Columbia 16
Yukon 23.2
Northwest Territories 33.7
Nunavut 24.7
Alberta 21.5
Source: Statistic Canada, Canadian Community Health Survey (CCHS), 2014.
2.3 Effects:
Obesity and overweight could cause multiple issues, including health risks and
economic consequences. From a health point of view, the World Health Organization
suggests that overweight and obesity have significant positive relationships with a
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number of chronic diseases, including diabetes, cardiovascular diseases, and cancer
which occur not only in the developed countries with high income but also in the low
and middle income countries, especially in urban settings (WHO, 2016). Moreover,
some research has analyzed the impact of body fatness on mortality; a J-or U- shaped
relationship between BMI and mortality has been reported in a number of US studies
(Lee & Manson, 1997); that is, mortality is higher at both high and low extremes of
body weight. In 2000, a Canadian study tested the proportion of all deaths among
adults 20-64 years old and found that overweight and obesity grew from 5.1% to 9.3%
between 1985 and 2000 (Public Health Agency of Canada, 2011). Another Canadian
study used the National Population Health Survey (NPHS) which has included 11,326
participants and followed them for 12 years from 1994/1995, and found that the
obesity category classⅡ or Ⅲ had a significantly increased risk of all-cause
mortality (Katzmarzyk et al,. 2004). For better understanding of the health effects of
obesity, the following discusses examples of diseases which are considered to be
related to body fatness and the impact of obesity on the economy.
Mokdad et al. (2003) studied the relationship between diabetes and obesity
among U.S adults in 2001. The self-reported data show a significant rise in obesity
over a one-year period (2000-2001); meanwhile, diabetes' prevalence has risen by
8.2%. Furthermore, a comparison was provided by that study between overweight
adults and normal weight adults. He used a logistic model to generate the odds ratios
(ORs) and their 95% confidence intervals (CIs) for the association of medical and
BMI conditions. Results show that compared to adults with normal weight, adults
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with a BMI of 40 or higher had an odds ratio (OR) of 7.37 for diagnosed diabetes, 6
for high blood pressure, 1.88 for high cholesterol levels, 2.72 for asthma, 4.41 for
arthritis, and 4.19 for fair or poor health. Both overweight and obese were associated
with diabetes, high blood pressure, high cholesterol levels, asthma, arthritis, and fair
or poor health status significantly.
Stanford Health Care states that the probability of having heart disease is 10
times higher for obese people than normal weight people. Joint problems are more
common in obese people. Obesity has different effects on men and women. Obese
women have a higher risk for breast cancer. Overweight in men could cause colon
cancer and prostate cancers.
From an economic point of view, several studies show that obesity and
overweight increase the burden of public health welfare. INSPQ (2014) published a
report illustrating what economic cost could be generated due to prevalence of obesity
in Canada. First is the direct cost, for example, the cost of hospitalization, medical
consultations in outpatient clinics and the consumption of medications. The other is
indirect cost referring to lost productivity when individuals must temporarily or
permanently leave work for health reasons. Trogdon et al. (2008) pointed out that
indirect costs also include insurance since compared with non-obese workers, obese
workers miss more workdays due to illness, injury, or disability. With higher life
insurance premiums and more workers’ compensation paid for employees who are
obese than for those who are not, the costs for employers become bigger. Meanwhile,
Colditz and Wang (2008) found obesity is associated with lower wages and lower
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household income. Konnopka et al. (2011) estimated the amount the German
government has to pay for the treatments of obese and overweight and the diseases
that caused by them and found that obesity caused 4,854 million EUR in direct costs
that corresponded to 2.1% of the overall German health expenditures in 2002 and
5,019 million EUR in indirect costs, 43% of direct costs that resulted from
endocrinology diseases like obesity and diabetes itself, followed by cardiovascular
diseases (38%), neoplasms (14%) and digestive diseases (6%). Sixty per- cent of
indirect costs resulted from unpaid work, and 67% of overall indirect costs were due
to mortality.
Another Canadian research program which use the CCHS, NPHS and Economic
Burden of illness in Canada, analyzed the impact of obesity on Canada economic
costs from 2000 to 2008. This study has calculated the effect of inflation on average
incomes and health care costs over that period. The study looked at both the direct
costs to the health system (i.e. the hospital care, pharmaceuticals, physician care and
institutional care) and indirect costs to productivity (i.e. the value of economic output
lost as a result of premature death and short and long term disability), which have
been defined as the economic burden of obesity. This study focused on eight chronic
diseases which have extensively been considered related to obesity, and found that
from 2000 to 2008, the annual economic burden of obesity in Canada increased from
$3.9 to $ 4.6 billion (Public Health Agency of Canada, 2011).
2.4 Potential Explanations for Obesity:
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Many studies have illustrated various possible economic explanations for the
prevalence of obesity, including income, education, food prices, etc. Meanwhile, some
medical reports also point out the potential physical reasons for obesity, like
decreased sleep, increased consumption of weight control medicine, etc. Most
researchers focus on a small number of the possible causes of obesity. This review
will focus on limited economic reasons, leaving the rest for further discussions.
A widely acknowledged opinion is that there is a negative relationship between
income level and obesity, which means as the income level goes up, the obesity rate
will go down. Jolliffe (2011) examined the impact of income on obesity by using data
from the National Health and Nutrition Examination Survey (NHANES) over 5 time
periods: 1971-1974, 1976-1980, 1988-1944, 1999-2002, and 2003-2006. For the data
setting part, the author grouped the data into two categories, poor and not poor, and
for all analysis in this study, poor was defined as less than or equal to 130% of the
poverty line. The author applied the unconditional quantile regression (UQR) to
analyze the differences between poor and non-poor, male and female,in overweight
and obese respectively. Also, the author used OLS regression to compare with the
UQR to get marginal effect of some explanatory variables on both conditional and
unconditional mean of the dependent variable. The study concluded that for the last
35 years, it was 5.1 to 6.5 percentage points more likely for poor people to become
obese than non-poor people, based on distribution-sensitive measures and that the
UQR estimator showed a strong relationship between income and BMI at the tails of
BMI distribution, while the UQR estimation indicated a negative relationship between
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an increase in income and BMI values.
Anca and Kurt (2013) used the Kuznets Curve to define the relationship between
income level and obesity. The Kuznets Curve (Akerman & Kuznets, 1955) was first
used to describe a country’s development with the progression of economic inequality.
They used panel data of the Behavioral Risk Factor Surveillance System (BRFSS) and
Current Population Survey (CPS) from 1991 to 2010. Through a difference- in-
differences strategy, they set the obesity prevalence as the dependent variable and
income level as independent variable, also including a fixed effect estimator. The
results suggest, at the first, the trends of obesity and income are the same, and then
obesity decreases with a continued increase in income. The peak of this curvilinear
relationship is $29,744 in total pre-tax income. However, the study included the fact
that the relationship between obesity and income level was limited to white females;
there is less evidence of similar results for white male.
Obesity is not only an issue in the United States but also a general problem in
Europe. The prevalence of obesity has increased by 10% - 40% in most European
countries over the last decade, Garcia and Quintana (2008) studied the relationship
between overweight, obesity and income level for both males and females using a
panel data set from the European Community Household Panel, Eurostat consisting of
eight waves from 1994-2001 years and from nine countries in Europe. Using BMI as
the dependent variable and dummy modality, they run OLS regression, multinomial
logit estimation and quantile regression for males and females respectively. Labor
income and other household income were treated separately. The results show that
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there was a statistically significant negative relationship between contemporaneous
BMI and own labor earnings for female, but there was limited relationship between
BMI and income for male in these nine European countries.
Using a sample of 56311 individuals from the Russia Longitudinal Monitoring
Survey (RLMS) from 1994 to 2005, Staudigel (2011) explored the relationship
between food prices; body mass and obesity for urban adult Russians-aged 18 and
above. The author used fixed-effect panel models to deal with unobserved individual
heterogeneity in the determinants of BMI. For investigating the probability of being
obese, a logit model was used. The main results showed that there was little evidence
supporting a relationship between food price and overweight and obesity in Russia;
the price of only a few foods, like milk and pork could affect the BMI of male and
female, respectively.
Using four U.S. nationally representative data sets, Mao and Yan (2013) showed
that eating habit plays a big role in obesity. They found that the overweight and obese
individuals consumed less vegetables and fruits, and higher calorie drinks compared
to the normal weight control groups even though the overweight and obese groups
had stronger intention to lose weight.
Brown et al, (2003) studied the relationship between sitting time, physical
activity and BMI in two control groups. Their study included variables age, number of
children, physical activity, sitting time, BMI, gender and work patterns. They ran
logistic regression to explore which factors contribute to obesity most among
participants. The results showed that compared with men in full-time work, women,
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regardless of work in full-time or part-time, or full-time home duties, were less likely
to be overweight or obese. Participants with high daily level sitting time are
significantly more likely to become obese, compared with participants with low level
sitting time. However, a major limitation of this study is non-random selection of the
participants with self-reported data.
Most recently, Wanner et al, (2016) explored the relationship between physical
activity, sitting time and different measurements of obesity. In their report, they used
Swiss Cohort SAPALDIA (SAP) to study the cross-sectional associations between
domain-specific physical activity, sitting time, and obesity, as well as longitudinal
associations between patterns of change in physical activity and weight ten years later.
They found that leisure time and physical activity have negative relationship with
obesity. However, that relationship only affects body fat significantly, not BMI.
Sarma et al. (2013), by studying the NPHS, finds that leisure-time physical
activities and working – time activities have a negative effect on BMI of Canadian
adults. Overall, cross-sectional and longitudinal results support the relationship
between physical activity and obesity; physical activity could contribute to weight
control.
Baum and Ruhm (2007) studied the relationship between age and obesity; their
results show that, in the U.S, for the populations above age 30, weight significantly
increased with age. Also many studies have showed that those with higher education
levels will have a lower risk of obesity. Rodolfo (2000) found that education has a
positive effect on reducing the probability of obesity. Devaux et al. (2011) studied the
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relationship between education and obesity among OECD countries. They focused on
adults aged between 25-64 adults in Canada, England, Australia and Korea. After
completing a logistic model, they found a broadly linear relationship between the
numbers of years spent in full-time education and the probability of obesity. They also
found that the more people are educated, the less probability there is for them to be
obese (the only exception being men in Korea). However, this negative relationship
was found to be significantly stronger in females than males, especially among the
candidates from England and Korea. This inverse relationship between education and
obesity exists due to several reasons: first, higher education leads to greater access to
health-related information; second, acknowledgement of risks that related to lift style
choice. However, the major limitation for this report is that BMI was measured in
England and Korea, but self-reported in Canada and Australia, which might cause
errors in estimation.
III Models and Data
3.1 Methods
To analyze the relationship between overweight/obesity, income and other
independent variables I described above, we begin with the following simple linear
equation:
BMI = 𝛽0 + 𝛽1 ∗ 𝑎𝑔𝑒 + 𝛽2 ∗ 𝑒𝑑𝑢𝑐𝑎𝑡𝑖𝑜𝑛 + 𝛽3 ∗ 𝑖𝑛𝑐𝑜𝑚𝑒 + 𝛽4 ∗ 𝑔𝑒𝑛𝑑𝑒𝑟 + 𝛽5
∗ 𝑤𝑜𝑟𝑘 𝑜𝑐𝑐𝑢𝑝𝑎𝑡𝑖𝑜𝑛 + 𝛽6 ∗ industry + 𝛽7 ∗ human behavior + 𝜀𝑖
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In a linear model, the residuals are assumed to be normally distributed. We could
observe whether those independent variables are related to obesity, but couldn’t
observe which independent variable is the crucial factor of obesity. In that case, it is
necessary to introduce logit regression and fixed-effect regression. Logistic regression
is very similar to linear regression but with binary dependent variable. By using logit
regression, I could identify which variable triggers the highest probability of
overweight. Here is the logit function
Ln (𝑝𝑟𝑜𝑏𝑖𝑙𝑖𝑡𝑦 𝑜𝑓 𝐵𝑀𝐼 > 30
1 − 𝑝𝑟𝑜𝑏𝑖𝑙𝑖𝑡𝑦 𝑜𝑓 𝐵𝑀𝐼 > 30)
= 𝛽0 + 𝛽1 ∗ 𝑎𝑔𝑒 + 𝛽2 ∗ 𝑒𝑑𝑢𝑐𝑎𝑡𝑖𝑜𝑛 + 𝛽3 ∗ 𝑖𝑛𝑐𝑜𝑚𝑒 + 𝛽4 ∗ 𝑔𝑒𝑛𝑑𝑒𝑟
+ 𝛽5 ∗ 𝑤𝑜𝑟𝑘 𝑜𝑐𝑐𝑢𝑝𝑎𝑡𝑖𝑜𝑛 + 𝛽6 ∗ 𝑖𝑛𝑑𝑢𝑠𝑡𝑟𝑦 + 𝛽7 ∗ ℎ𝑢𝑚𝑎𝑛 𝑏𝑒ℎ𝑎𝑣𝑖𝑜𝑟
+ 𝜀_𝑖
Since panel-data has been included in my study, if the model above contains all
observed individual effects, then OLS estimator will be consistent and efficient.
However, with unobserved individual effects, or if the unobserved effects are
correlated with the explanatory variables in my model, the estimator will become
inconsistent and biased. The theories of Wooldridge (2010), could explain my
dilemma well. On one side, using panel data would reveal the relationship between
observed individual effects and included independent variables; on the other side,
there are suspicious unobserved individual effects that may be correlated with
independent variables. Since there are so many social economic factors included in
my model, they are generally endogenous. It is necessary to introduce fixed – effects
regression to help me solve my dilemma. If there are omitted variables, and these
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variables are correlated with the variables in the model, then fixed effects models may
provide a means for controlling for omitted variable bias. Fixed effects models control
for the effects of time-invariant variables with time-invariant effects. This is true
whether the variable is explicitly measured or not.
To better understand the contributions of individual predictors, we need to
examine the regression coefficients. In linear regression models, the changes in each
unit changes predictors, which we use the regression coefficients to represent. In
logistic regression, the regression coefficients imply the change in logit for each unit
change predictor. Therefore, based on the logistic regression model, people will use
odds ratio to quantify the effect size. Odds ratio is the ratio of relative risks that
represents the change in an outcome (y) from a change in variable (x). The following
equation shows the definition of odds ratio.
𝑂𝑑𝑑𝑠 𝑅𝑎𝑡𝑖𝑜 =𝑃(𝑌 = 1|𝑋 + 1)/𝑃(𝑌 = 0|𝑋 + 1)
𝑃(𝑌 = 1|𝑋)/𝑃(𝑌 = 0|𝑋)
(Note: Y=0 means y equal to the based category);
In this paper, I will use odds ratio to represent results for each set of control variables.
Each table contains the results as I have controlled the independent variables like
household income, industry, work occupation and human individual behavior
separately.
In my research, the main purpose is using the logit regression and fixed effect logit
regression to analyze the relationship between obesity and the work occupation under
different industries by using CCHS and NPHS data.
3.2 Data
19
To focus on building the health information system, Canadian Community Health
Survey (CCHS) uses cross-sectional questionnaires to collect health related
information like health status for the Canadian population. Similarly, the National
Population Health Survey (NPHS) uses longitudinal methods to collect information
about how economic and fiscal situation affects health care systems, and the health
status of Canadians.
The differences between those two surveys are 1) The changing of health status
related to many conditions, for example, public policy development and health care
utilization; NPHS contain more details about those conditions compare to CCHS. 2)
Because of a lager sample size, the CCHS is able to act as a data source on small
population and rare characteristics; NPHS consists of separate households, health
institutions, and north components. 3) For the NPHS, the earliest year of data is
1994-95, and the survey was conducted every two years until 2011; CCHS began their
survey in 2001-16. 4) For the sample size, the total sample of CCHS which I used in
my regression is 274351; the first cycle of NPHS contains 17,276 respondents and
keeps declining over the cycles. Both surveys are used in this study
For this paper, two kinds of data-sets have been selected to complete the analysis-
cross sectional and panel. The longitudinal data utilizes Statistics Canada’s National
Population Health survey (NPHS) and the cross sectional data comes from the
Canadian Community Health Survey (CCHS). Both of them collect information
related to health status, health care utilization and health determinants of the Canadian
20
population.
3.2.1 CCHS
The target population of CCHS covers Canadians over 12 years old, who live in the
ten provinces and the three territories. Three groups of people are excluded from the
survey’s coverage: candidates who are living on reserves and other Aboriginal
settlements in the provinces; people who are full-time members of the Canadian
Forces; the institutionalized population and people who live in the Quebec health
regions. Those three groups of people represent less than 3% of the Canadian
population aged 12 and over. The main purposes of the survey are health surveillance,
population health research and convenience in every field of study for researchers
who use this information to improve Canadian’s health.
In 2001, Statistics Canada and Health Canada began the first survey and repeated
it every two years as one cycle until 2005. The Canadian Community Health Survey
changed data collecting from every two years to annually from 2007.
3.2.2 NPHS
The National Population Health Survey (NPHS) was designed to collect health and
related socio-demographic information of Canadian population including household
residents in ten Canadian provinces since 1994/1995. However, in the last cycle the
survey was extended to cover all of Canadian including three territories and people
who moved to the US.
21
The households, the health institution, and the North components are the three
main data resources of NPHS; in this paper I will focus on the household only. In
1994/1995, the NPHS started the first survey and repeated it every two years as a
cycle, until 2010/2011; NPHS contains nine cycles in total. For the first three cycles
(1994/1995, 1996/1997 and 1998/1999), the data are both longitudinal and
cross-sectional with original samples from cycle 1. From cycle 4, NPHS became
strictly longitudinal.
The questionnaire of NPHS was designed by specialists from Statistics Canada,
provincial ministers of health and other researchers in academic field. In order to
choose samples that represent the real situation of all Canadian populations; Statistics
Canada also adjusted to create different longitudinal weights. In this report I use the
longitudinal square weights provided by Statistics Canada
There were 17276 Canadians of all ages chosen as the observations for the
NPHS first cycle. Unlike the calculation methods of other cycles’ response rates, the
response rate of the first cycle was based on 20095 in-scope respondents. The rest of
the cycles’ response rates were based on the 17276 individuals who responded in
Cycle 1. As time passed, the respondents decreased from more than 17276 to 12041;
furthermore, the NPHS lost almost half of applicable results due to incomplete
responses. The response rates are 83.6%, 92.8%, 88.3%, 84.9%, 80.8%, and 77.6%,
77.0%, 70.7% and 69.7% respectively. In my research, data are selected from cycle 1
to cycle 9 and I restricted the age group from 20 to 50 in cycle 1. For the last cycle the
largest age of the samples is 67 and not beyond the retirement age. Therefore, 8401
22
individuals are selected as my regression sample in cycle 1; afterwards, only 4619
observations are left in the last cycle for me to analyze.
3.2.3 Descriptive Statistics
In this paper, I used 8 cycles of data from 2007 to 2014. Given the focus of my study
on the relationship between obesity and occupations, I restricted the age from 25 to 65
years old in each cycle. Meanwhile, I treated the values which are not applicable, not
stated and refused as missing data, and therefore deleted those observations. Also
pregnant women were also removed from the data because their body weight will
affect the true value of their BMI. In the end, there are 274,351 observations left for
the regression. The following four charts represents the tendency of normal weight,
overweight and obese in relation to highest completed level of education, level of
household income, four groups of work occupations and nine types of industries.
Figure 2 shows the relationship between completed highest level of education and
normal weight, overweight and obese respectively. Overall as the completed
education level goes up, obese population becomes lower (25% to 11%) of all, and
normal weigh population grows from 35% to 53%.
Figure 2: Relationship between BMI and highest level of education (CCHS)
23
Figure 3 represents the relationship between household income and body weight,
normal weighted population decreased as household-income increased. Overweight
and household income move in the same direction, which indicates higher income is
associated with higher body weight (overweight population grows from 15% to 35%).
However, the tendency of obesity is a pretty flat line, probably due to low sample
sizes at the very low income level.
Figure 3: Relationship between BMI and household income (CCHS)
Figure 4 shows the population distribution among four work occupation groups1. As
we can see, group 2 and group 3 contain the largest normal weight population, and
1 Occupation 1 contains managers; Occupation 2 includes business, finance and administration occupations,
natural and applied sciences and elated occupations, health and education occupations; Occupation 3 consists of middle management in retail, sales and service; Occupation 4 included middle management in transportations, agriculture and manufacturing.
0102030405060
Normal
Overweight
Obese
0102030405060
Normal
Overweight
Obese
24
group 1 and group 4 contain the largest overweight and obese population.
Figure 4: Relationship between BMI and work occupation (CCHS)
Figure 5 represents the relationship between industries and body weight. The lowest
body weight occurs when the industry is related to health and education, and the
highest body weight occurs when the industry is related to mining and construction.
Figure 5: Relationship between BMI and 9 groups of industries (CCHS)
In the descriptive statistics, I treat cycle 5, 2004/2005 as cross-sectional data, since
data from those two years contain the most individual characteristic variables that I
used in CCHS. That makes it convenient for me to perform comparisons between the
CCHS and NPHS. The following figures come from Cycle 5 only.
From Cycle 5, Figure 6, the relationship between education and obesity is overall
negative. From the starting point, the percentage of normal weight people keeps
0 10 20 30 40 50 60
Occupation 1
Occupation 2
Occupation 3
Occupation 4
Obese
Overweight
Normal
0102030405060
Normal
Overweight
Obese
25
growing as their highest completed education level increases, which indicates a rise
from 25% to 50%. At the same time, the tendency of overweight people and obese
people is towards the opposite direction which decreases from 35% to 25% and 25%
to 9% respectively.
Figure 6: Relationship between BMI and highest level of education (Cycle 5,
NPHS)
Figure 7 shows that: as income increases, people’s body weight index increases as
well. People are less likely to be obese but more likely to be overweight; the
overweight population rises from 20% to 39%.
Figure 7: Relationship between BMI and household income (Cycle 5, NPHS)
0102030405060
Normal
Overweight
Obese
0.0010.0020.0030.0040.0050.0060.00
Normal
Overweight
Obese
26
Figure 8 reflects the relationship between occupation2 and BMI. People who work in
the business and finance sector have the lowest chance of becoming obese, which
forms the biggest portion of the population. This contrast with other occupations like
managers, who spend most of their time sitting behind desks. Workers in sales and
service, transportation and trade department are involved in a lot of physical activities
in their daily work, and have higher chance to become overweight and obese.
Figure 8: Relationship between BMI and work occupation (Cycle 5, NPHS)
Figure 9 shows the relationship between industry and body weight; it turns out that
people who work in education industry and entertainment industry have a lower
chance of being obese. Agriculture, mining, manufacturing and public administration
industry contain the largest obese and overweight population.
Figure 9: Relationship between BMI and industry (Cycle 5, NPHS)
2 Occupation 1 contains managers; Occupation 2 includes business, finance and administration occupations,
natural and applied sciences and elated occupations, health and education occupations; Occupation 3 consists of middle management in retail, sales and service; Occupation 4 included middle management in transportations, agriculture and manufacturing.
0 10 20 30 40 50
Occupation 1
Occupation 2
Occupation 3
Occupation 4
Obese
Overweight
Normal
27
3.3 Variable Description
3.3.1 Dependent Variable
The two dependent variables of the study are dummy variables indicating whether or
not a person is overweight or obese. According to the WHO (2012) classifications and
Health Canada, body mass index of 18.5- 24.9 is normal weight, from 25.0 to 29.9 is
overweight, greater than 30.0 is obese. An individual is considered to be obese when
her or his BMI (a measurement obtained by dividing a person's weight in kilograms
by the square of height of the person in meters) equals or exceeds 30 kg/m (Health
Canada, 2003). The NPHS uses height data and self-reported weight to estimate BMI.
The respondents select the exact height and weight, and then are classified as
underweight, normal weight, overweight or obese. In my study, I will focus on
overweight and obese only.
3.3.2 Independent variables
3.3.2.1 Age
In NPHS, household respondents provide their accurate date of birth, according to
0102030405060
Normal
Overweight
Obese
28
which, age has been calculated. Each sample in cycle one must complete the general
questionnaire. There were 2022 observations selected from cycle one and who
continued to be interviewed from the second cycle until 2011, which means I could
observe the BMI changes over 17 years to determine the relationship between age and
obesity.
3.3.2.2 Education
In questionnaires, the respondents need to tell what is the highest level of education
they have ever attained; they may also answer questions about what level of education
they are attending now, how many years of study they have finished, and what is their
student status (part-time or full -time). Those questions could help me to gather the
education background for respondents and keep tracking their education level.
3.3.2.3 Gender
A lot of research illustrates that compared to men; women are more vulnerable to
weight change. The study of Case and Menendez (2009), reveals that women in South
Africa face a higher risk of obesity; similarly, Burke and Heiland (2008) find that
women from different races face different risks of obesity; however, this is not
standard for men. In my work, gender has been treated as a control variable so I could
study the potential relationship between BMI and gender. I define the variable
“female” equal to 1 if the individual is a female and zero otherwise.
3.3.2.4 Household income
As a critical factor, income has been considered as an important determination of BMI.
There is divergence between many studies. Some of the results support that income
29
could affect BMI, some of them do not. For instance, Cawley (2008) tested whether
income has an effect on BMI of elderly Americans by using data from National
Health Interview Surveys, his empirical results denied the existence of that effect.
However, Grecu and Rotthoff (2013) found that there is an obesity Kuznets curve for
white females, which means, as income increases, BMI will increase then decrease.
NPHS set up a series of detailed questions to help me collect necessary information.
For the household, the respondents were asked to answer what the sources of their
income were from 13 categories, which are wages and salaries, income from
self-employment, dividend and interest, employment insurance; worker’s
compensation, benefits from Canada or Quebec pension plan, retirement pensions; old
age security and guaranteed income supplement, child tax benefit; provincial or
municipal social assistance or welfare, Child support, Alimony and Other. Then, they
were asked to pick one source as their main income source from those choices above,
and give an estimation of their household income for past 12 months. For individual,
the respondents have to classify their income into one range by 12 months; the
minimum is below $5000, and the maximum is above $10, 0000.
3.3.2.5 Work occupation
NPHS and CCHS contain a labor force chapter to ask respondents what work
occupation they currently have, or what work occupation they used to have. For
example, “What kind of work are/were you doing?” From those questions, I collect
the information about respondents’ occupations. Inas and Dhaval (2012) found that
blue-collar work is associated with a higher probability of being obese. In order to
30
observe the influence of work occupation on overweight and obesity based on the
National Occupational Classification, I re-categorize the work occupation into 4
groups with similar production processes and skill requirements. Group 1 contains
managers, group 2 includes business, finance and administration occupations, natural
and applied sciences and related occupations, health occupations, occupations in
education, law and social, community and government services; occupations in art,
culture, recreation and sport. Occupation 3 consists of middle management
occupations in retail, whole-sale trade, customer service, sales and service
occupations. Occupation 4 includes middle management occupations in trades,
transportation, production and utilities; trades, transport and equipment operators,
related occupations; natural resources, agriculture and related production occupations,
occupations in manufacturing and utilities. (Group 1 is reference group.)
3.3.2.6 Industry
NPHS and CCHS ask respondents “What’s the name of your business?” “What kind
of industry is this?” From those questions I collected the information about
respondents’ industries. A Statistics Canada report suggests that workers in trades,
transport are more likely to be obese than workers in financial and administration.
Based on the North American Industry Classification system, I re-categorize the
industries into 9 groups respectively with similar production processes and skill
requirements. For example, industries like public administration require the highest
administrative skills, which limit their daily physical activities during working time.
Manual worker such as constructors and mining workers require the least
31
administrative skills but highest physical activities during their regular working time.
In the control group, agriculture, forestry, fishing and hunting are involved. Mining,
construction group consists of mining, quarrying, oil and gas extraction, utilities and
construction. The third one is manufacturing group. Whole-sale and retail trade group
including whole-sale trade, retail trade, transportation and warehousing. Next is the
public administration group. In the finance and insurance group, information; finance
and insurance; real estate and rental and leasing; professional, scientific and technical
service; management of companies and enterprises, administrative and support and
waste management and remediation service are included. Education service, health
care and social assistance make up the education, health group. The entertainment
group includes arts, entertainment and recreation; accommodation and food services.
In the other services group, other services exclude public administration. In addition,
table 12 and 13 in the appendix show the re-categorization of work occupations and
industries.
3.3.2.7 Eating habits
Eating habits define how people eat and which foods they intake. The CCHS and
NPHS focus on the frequency of respondents eating green salad, fruit, fruit juice and
potatoes. Questions include “Not counting juice, how often do you usually eat fruit?”
“How often do you eat green salad?” The respondents need to describe the frequency
using terms such as per day, per week, per month, per year or never. Through those
questions, I will be able to find the relationship between individual behaviors and
BMI.
32
3.3.2.8 Physical Activity
NPHS has divided physical activity into two sections, leisure-time physical activity
and working-time physical activity. Leisure-time activity includes walking for
exercise, gardening and yard work, swimming; bicycling, popular or social dance,
home exercises, ice hockey, ice-skating, downhill skiing or snowboarding, jogging or
running, golfing, exercise class or aerobics, cross-country skiing, bowling, baseball or
softball, tennis, weight-training, fishing, volleyball, basketball, in-line skating or
roller-blading, yoga or tai-chi, and all other reported activities, Work time activity
includes the usual daily activities or work habits, respondents have to select from the
following four answers: 1,“usually sit during the day and don’t walk around very
much”, 2,“stand or walk quite a lot during the day but don’t have to carry or lift things
very often”, 3, “usually lift or carry light loads, or have to climb stairs or hills often”,
4, “Do heavy work or carry very heavy loads”. The respondents were asked to report
which activities they participated in during leisure-time, how often they did them do
and how long they spend on those activities.
3.3.2.9 Drink type and stress at work
Both NPHS and CCHS data classified the frequency of how often respondents drank
in the past twelve months, from daily drinker, weekly drinker, monthly drinker to
never drink. According to National Obesity Observatory’s (NOO, 2012), alcohol
might become a component of the risk for weight gain. Also, in NPHS and CCHS
data, they classified the stress at work as dummy variables. NPHS focused on whether
respondents were satisfied with their job and CCHS aimed to find out whether they
33
have had stress during respondents’ work. In 2007, Susan (2007) used the longitudinal
studies and proved that stress at work may be causally linked to weight gain.
IV Results
Tables 4 and 5 show the results for overweight and obese, respectively. Both tables
use the cross-sectional CCHS data. Tables 6 and 7 illustrate the results of the
overweight and obese as the outcomes of general logit estimation model by using the
NPHS data (Cycle 5). In addition, Tables 8 and 9 show the fixed effect logit results of
the NPHS data (all Cycles). The data set of each respondent in NPHS could be treated
as panel data since it is longitudinal. If I pick one of the nine cycles, and only focus on
those two years, data in that cycle could be treated as cross-sectional data. In Tables 6
and 7, I treat the cycle 5 of NPHS as cross-sectional data, and used cycle 5 to do the
estimation only for reasons given in the data description part.
4.1 CCHS Result
Table 4, Logit model based on overweight as outcome (CCHS).
The base model of Table 1 shows the coefficient for female is statistically significant
at the 1% level and negatively correlated with overweight. This implies that the
probability of females being overweight is 18.1% less than for males. The coefficient
on age is significant at the 1% level and positively correlated with overweight. This
indicates that as respondents’ age increases, the probability of becoming overweight
34
will increase 1.29% for each additional year. The reason for that may be lack of
physical exercise and eating more. Meanwhile, metabolic generation rate will
decrease and fat content will increase. For the urban variable, it is statistically
significant at 1% level and compared to the people who live in rural areas, the urban
people are less likely to be overweight. A possible explanation is that the fitness
facilities are more complete and convenient in urban areas, and people can receive
health information from multiple channels like advertisements and the internet. The
coefficients of most provinces are statistically significant at the 1% level except
Northwest Territories and Nunavut, which means compared to Newfoundland and
Labrador, people who live in other provinces (not including Northwest Territories and
Nunavut) are less likely to be overweight. For example, people living in New
Brunswick will have a higher risk of being overweight compared to those who live in
British Columbia. Northwest Territories is not statistically significant at the 10% level
and people who live in Nunavut are more likely to be overweight than people who
live in Newfoundland and Labrador. For the education variable, people with less than
9 years of education form the control group. The coefficients for each education
variable are all statistically significant at 1% level. As the education level increases,
the risk of being overweight decreases. That fits my hypothesis very well: with higher
education level, people are likely to play an important role in society, which lead them
to pay attention on their appearance, which force them to consume low calorie food
and go to the gymnasium regularly.
For the second regression of Table 4, I added household income categories to the
35
list of control variables. Coefficients of all other variables changed very little with the
introduction of controls for family income. Except for the control group, household
income equal to zero, the rest of the household income groups are statistically
significant at the 1% level. Individuals with no household income have the lowest
body weight compared with other categories; the highest risk group of being
overweight is household income of 10K-14.999K with odds 45.6% and significant at
the 1% level. However, from the range 10K to 59.9K, the risk of being overweight is
decreasing smoothly.
The results from the third regression show that both industries and work
occupations are statistically significant at 1% level. For the industry category, I treat
agriculture, forestry, fishing and hunting as the base group and the coefficients for the
remaining groups are all positive and the odds show that the people in following
industries are more likely to be overweight: Mining 13.27%, Manufacturing 0.778%,
trade 28.59%, Finance 21.45%, Education, 34.61%, Entertainment 10.88%, Other
services 15.22%, Public administration 35.95%. For the work occupation, compared
with major occupation 1, major occupation 2 and occupation 3 are less likely to be
overweight and statistically significant at 1% level with the odds 5.92% and 5.66%
respectively. The odds ratio of overweight in major occupation 4 is 1.08% higher than
major occupation 1. The trade, finance, education and public administration industries
require are less physical, compared to others. That might be the main reason for their
higher than normal odds to become overweight.
The effects of gender, age, regions and provinces in the third regression are
36
similar that in the second equation. Also the coefficient of household income changes
a lot compared with the second regression, the coefficient of selected groups from less
than 5k to 50 k-59.999 k become negative. As income increases, the risk of being
overweight increases. That might be due to a correlation between household income
and occupation.
In the fourth regression, human individual behavior variables are added to
observe the effect of eating habits and physical activity on overweight and obesity.
The results of male, age, region of residence, province, education, and industry and
work occupation show no obvious differences compared to those in the third
regression. The coefficients for the eating habits, drinking fruit juice, eating fruit,
eating carrots and other vegetables are all statistical significant at the 1% level, which
means eating healthy food daily will decrease risk of being overweight. Physical
activity during leisure time is significant at the 1% level which means people not
involved in leisure time activity will suffer a higher risk of being overweight at
39.06%. Drinking type is statistically significant at the 1% level. Occasionally
drinkers and abstainers are more likely to be overweight compared with regular
drinker. That is against my prediction; the reason for this may be because the question
for this survey is based on the last 12 months, and the sample that already is
overweight may give up drinking to reduce weight. Finally, the results show that
stress work has a higher risk becoming overweight.
Table 5 contains the results of general logit regressions using obesity as outcome
(CCHS).
37
For the base model, the results of female, age and region of residence are quite similar
to the results for overweight reported in Table 4. For the province, compared with the
control group (Newfound land and Labrador), people who live in Nunavut are 24.47%
less likely to be obese statistically significant at the 1% level. Another difference for
the province variable compare to table 4 is that people who live in the Northwest
Territories are less likely to be obese, which is statistically significant at the 1% level.
The relationship between education and obesity is similar to table 1 except people
with trade and college certificate are more likely to become obese.
For the second regression of Table 5, the relationship between income and
obesity is positive. Compare to the result of regression three in Table 4, the results of
regression three in Table 5 shows a U shape, which means income could decrease the
probability of obese but increase that probability after passing some threshold. Results
also show that as income increases the risk of not being obese increases from 21% to
33.1%; after the total household income meet 29.99K, the probability of people not
being obese decreases. For the industry variable, the only difference is that the group
of people who work at art, entertainment, recreation; accommodation and food
services are less likely to become obese compared to the base group. The only
difference for the occupation variable among those two regressions is that results in
Table 5 shows people who work at occupation 2 and occupation 4 are less likely to be
obese.
After adding individual behavior variables in the fourth regression, the gender,
age and region of residence have the similar results compared to Table 4. The only
38
difference in the province variable in the two tables is people who live in Nunavut are
9.2% less likely to become obese. In general, the following variables have similar
results among those two regressions: education, household income, industry, work
occupation, physical activity, drink type and stress of work. The differences in those
tables are eating fruit per year and eating carrot per month. In Table 5, eating fruit per
year and eating carrot per month will decrease the probability of being obese.
4.2 NPHS result:
As I mentioned before, Cycle 5 of NPHS has more individual characteristic variables
that those in CCHS. The results of the base model in Table 6 clearly show that the
variable of age and gender are statistically significant at the 1% level. Compared to
males, the risk of females being overweight is 59.7% less. On the other hand, with
each year of age the odds increased by 3.13% for being overweight per year. For the
province variable, due to insufficient amount of respondents from Yukon and Nunavut,
the regression drops observations from those two territories. People from Ontario,
Quebec, British Columbia and those who moved to the United States have lower risk
of being overweight. Compared with the people whose highest education level is less
than 13 years, the odds of being overweight decrease with increasing education level
and all are significant at the 1% level.
When we add household income into the regression, the situation for the female,
age and province stay the same with the base model in Table 6. And the only
difference for education is for people with secondary education level; the result
39
becomes insignificant. Due to the insufficient sample size of no household-income
groups, I dropped those groups from all regressions, because I focus people who are
employed and have household income, for that I treat household income less than 5K
as control group. Except the household income below 9.9K and above 80K, people
have higher household income have lower risk of overweight. Above household
income of 29.999K, as household income increase people face higher probability to
become overweight. The reason for excluding those groups is because the numbers of
respondents in those two groups are too small.
For the third regression in Table 6, industry and work occupation variables are
added to the regression. Overall, the results of female, age, province and education are
not much difference from those in the second regression. However, the coefficient of
household income in the third regression becomes negative from 15K to 39.999K
although the tendency of income and overweight is same. Compared to the base group,
all industries have negative relationship with overweight which means people who
works at those industries are less likely to become overweight, especially people who
work at entertainment industry have lowest probability of being overweight with odds
lower by 33.84% and significant at the 1% level. The relationship between occupation
and overweight is negative, which means compared to manager jobs, people who have
business and finance; sales and service; trades and transportation job are more likely
to keep their body weight in normal range.
For regression 4, one of the notable differences with regression 3 is the
relationship between education and overweight. The higher the completed education
40
level the less likely people are obese. This result matches my hypothesis. The other is
the relationship between household income and overweight. As I mentioned before, in
regression three the effect of income is not stable, it changes between positive and
negative. However, in regression 4, the overall effect is positive, which means that as
income increases, the probability of not being overweight decreases by 39%, but still
keeps people less likely to become obese.
With respect to eating habits, the more frequently people eat fruit and veggies, is
the lower is the risk for them to become overweight. Compared to those people who
never do physical activities in their leisure time, people who spend time on those
activities achieve their lower risk of being overweight. Compared to monthly drinkers,
weekly drinkers and daily drinkers are less likely to become obese, which is similar to
the results obtained from using the CCHS data. The stress in work could cause big
issues for one’s health; the more people satisfied with their work, the lower risk for
being overweight.
Table 7 shows the results when obesity is used as the dependent variable. The
regression results of the base model are similar to what I got in Table 6 which
overweight as the dependent variable: compared to males, females are less likely to be
obese; meanwhile, age has a positive effect on the likelihood of obesity. People from
Saskatchewan and New Brunswick are more likely to suffer obesity problems among
all provinces except Yukon and Nunavut. Education has a positive influence on
people’s body weight, as the higher level of education you completed, the lower the
41
probability of being obese.
When I controlled for additional variables:
household income, compare to base model, female have lower risk to become
obese; regression results of age and provinces are similar as base model;
even though when people’s highest completed degree are secondary and college
certification which are higher than 9 – 13 grades, they are more likely to become
obese; the overall relationship between obesity and education stay the same;
compare to control group, when household income reach 5K to 9.99K, people
have lowest risk to become obese, for the rest household income ranges, as
household income increased they have better management on their body weight.
compare to the results in table three, household income has significant positive
effect on obesity control.
After adding industries and work occupations as the new independent variables for
model 3, the odds of female, age, province and education are almost the same as in
the second regression, except the p value of province Manitoba become statistically
significant at the 1% level and the p- value of people who have college certifications
changes to insignificant. The overall tendency of the household income variable does
not change, however the odds ratios become bigger for all income ranges. Compare to
regression three in table three, this result fits my hypothesis better. People who work
in mining and construction industries have the highest risk of being obese among all
industries with odds 14.06% and statistically significant at the 1% level. For work
occupation, it is clear that people who work as sales and services will have the highest
42
probability of obesity. Compared to the results in regression three table three, the
overall relationship does not change.
From the fourth regression of Table 6, the coefficient of mining and construction
industries used to be strictly negative and people who work at other services are more
likely to become overweight. However, the results I got in Table 7 appear to be the
opposite: people who work at the mining and construction industries suffer the highest
risk of becoming obese. And the insignificant results from the eating habits variable
are not supportive for my assumptions which might be due to the sample size being
too small. Moreover, the results for the job satisfaction, drink type and physical
activity during leisure time stay the same as the same model in Table 3. Since the odds
of physical activity at leisure time becomes bigger, which means compared to people
who are involved in leisure time physical activities, people who don’t participate
leisure time physical activities will suffer 93.94% higher risk of being obese, and that
suits my prediction very well.
4.3 NPHS (Longitudinal) Results
Since the NPHS is the longitudinal data set, I use fixed effect model in which, time
invariant variables such as gender, highest level of education and province are
excluded from regressions. The first regression controlling for household income
indicates that age has a negative effect for people to manage their body weight, which
means that as age grows, the risk being overweight will increase by 18.02% and
statistically significant at the 1% level. Furthermore, household income has a negative
43
effect for body weight control, as income increase the risk of being overweight
increases.
In the second regression, industry variables are added into my model. The
regression results of age and household income are consistent with those from the
base model. The regression results show that, no matter in which industries people
work, they are all suffering higher risk of being overweight than people work in the
agriculture industry. The third model uses work occupation instead of industry as
control variables. In general, age and household income stay the same as in the second
model. Compared to management occupations, business and finance occupation will
raise the probability of being overweight.
Adding controls for eating and physical activity behaviors makes a substantial
difference to the estimated coefficients. The coefficient of income becomes negative
and the probability of being overweight decreases at first; after the household income
reaches 30k to 39.999k the risk being overweight increases as income grows. The
relationship between being overweight and industry becomes negative, which is
different compared to regression two. Compared to agriculture, people who work at
the other industries have a lower risk of being overweight. Furthermore, the results of
trade and transportation become statistically insignificant, and people who are in sales
and services are more likely to become overweight with the odds 4.54%, significant at
the 1% level. For the eating habit variable, drinking fruit juice regularly will lower
risk of being overweight. On the other hand, the other results are not what I had
expected. To understand the reasons why the regression results in model four changed
44
so rapidly, I have done a variable test with the same observations in model four, and
the results show that the main cause is individual characteristics variables added into
the regression with undersized sample (as opposed to the change in the sample size).
Table 9 shows the results of fixed-effect regressions using obesity as the dependent
variable and the longitudinal NPHS data.
First, from the first regression, we see that the coefficient on age is statistically
significant at the 1% level and positive correlated with obesity. The coefficients of
household income are negative, however, as increasing household income increases
the risk of being obese. For the second regression, after industry is added into the
regression, the results of age and income are almost the same as those in the base
model. The coefficients of industry and obesity are positive, especially for those
people who work at finance and insurance industries; people who work at other
services are more likely to become obese. However, due to small sample size, the
results may be less reliable. For income below $40K in the third regression, increases
in household income could help control body weight; however, when household
income reaches $40K to 49.99k and above $60K, income has a negative effect on
obesity. Compared to managers, all other occupations have positive benefit for
people’s body weight management.
4.4 Link-test and Hausman test
As link-test examines whether a model has been properly specified; I have done the
link-test for CCHS and NPHS regression respectively. However, after having tried
45
many methods the results of the variable _hat and _hatsq still are all statistically
significant, means there still some variables that related to BMI but not have been
included in my regression. The main reason might due to the variables I selected are
all dummy variables.
To check whether the non-observed factors should be dealt with by a random effect
model or fixed effect model, I have done the Hausman test to found out if the null
hypothesis is true or not. In this report, the result after the Hausman test shows that
the null hypothesis was not true, which means the random effect model is inconsistent,
hence, fixed-effect model could be used in my report to deal with the panel data.
V Discussion
The results from using CCHS, NPHS cross-sectional and NPSH panel data are
consistent with most of the variables included and consistent with what has been
found in other research. Jungwee (2009) analyzed the relationship between obesity
and work occupation and found that employed males are more likely to be obese than
females. Similarly, according to CCHS and NPHS data the risk for female being
overweight is 25.7% and 69.9% lower than males respectively. The probability of
females being obese is 59.4% lower than males in the CCHS data regression analysis
and 35.5% based on NPHS data regression estimate. Age as a variable also followed
my expectation: with aging, people are more likely to be overweight and obese. For
the province variable, people living in British Columbia, Quebec and Ontario have the
46
lowest risk of being overweight and obese while people living in lower GDP
provinces will suffer higher risk of being overweight and obese. However, some
territories’ results are omitted in the NPHS regression result because of insufficient
samples.
Education has direct and indirect effects on the likelihood of being overweight
and obese. The direct contribution is: educated individuals make better use of
health-related information than those who are less educated (Speak et al., 2005). Also,
it is possible that highly-educated people have the knowledge to develop healthy
lifestyles and have more awareness of the health risks associated with being obese
(Yoon, 2006). For the indirect effect, education levels could determine the individual’s
social economic conditions, like income and work occupation. In my NPHS
cross-sectional estimation, the results confirm the well-known negative relationship
between highest education levels and probability of being overweight and obese.
Overall, for the CCHS regression results, the tendency is that as higher levels of
education are achieved, the risk of people being obese decreases. However, there are
exceptions at the trade certificate and college levels; people at these levels have a
higher probability of being overweight and obese. A possible explanation for this
result could be that education is correlated with other variables in this model, for
example, work occupation and household income.
Koffi (2014) found that income has a negative impact on both BMI and obesity,
which means increased income will slow down the growth of the population
becoming obese. However, my finding has a contrary result; compared to middle-high
47
income group, zero income groups have the smallest probability of being obese. The
difference might be due to the following reasons: first of all, we use different model to
do the estimation: I use the logit and fixed effect logit model, they used the OLS and
2SLS model. Second, I used a different period of CCHS data, particularly data from
2007 to 2014, while they used data from 2000 to 2009. Moreover, Tjepkema (2006)
used the 2004 CCHS data to analyze the impact of socio-economics on obesity; he
found that, compared to the middle income people, the high income group was less
likely to be obese, which contrasts with my CCHS estimation. In my research, I found
that the highest household income groups suffer higher risk of being overweight and
obese than lower household income samples. As Tjepkema (2006) tested how
different household income levels will affect BMI while each family contains same
number of people, I tested how different level of household income will affect BMI
regardless how many people were in one household This might account for the
difference in findings. The other possible cause of my results could be due to the
household income variable being correlated with work occupation and individual
behavior.
The results from the fourth CCHS data regression show that regular intake of
fruit and vegetables have a positive contribution to control people’s BMI. However,
the regression results from NPHS cross-section and panel data are not significant
enough to support my assumption, which might be due to insufficient sample size.
Still, people should be encouraged to eat more fruits and vegetables. For all three
datasets, physical activity at leisure time is a factor for being overweight and obese.
48
This was noticed when comparing active people to those who have never participated
in physical activity at leisure time in the last 12 months. The job satisfaction variable
in NPHS data is similar to the stress of work variable in CCHS data; both of them
measure the emotional condition of employed respondents. Results from CCHS data
show that people who are satisfied with their work will have higher risk of being
obese. This is contrary to the results from the NPHS panel data, which might be due
to inadequacy of the regression samples. It is common that people regularly drink
alcohol will have better BMI if they already suffer other health issues and which
causes their body weight to decrease, or due to the health issue they could better
control their body weight.
The following two tables summarizes the overall relationship of industry, work
occupation and BMI; I rank industry and work occupation from the highest risk of
being overweight and obese to the lowest risk of being overweight and obese. From
the CCHS data, the individual behavior variable has a minor effect on risk ranking of
all industries. People who work for the public administration and education for last 12
months have the highest risk of being overweight and obese. This might be due to the
good social welfare and sedentary working environment. Mining, finance, trade,
manufacture and other service are in the middle range. People who work in those
industries have a lower risk of being overweight and obese compared to people
working in public administration and education. This is possibly because people
involved in these groups are less sedentary. Agriculture and entertainment industries
are at the lowest range. Here are some possible explanations: First, agriculture
49
industry involves agriculture, forestry, and fishing and hunting, which requiring a lot
of outdoor physical activity. Second, people who work in entertainment industry
should maintain good body shape, which makes them have the lowest risk of being
overweight and obese. On the other hand, the results show in NPHS cross-sectional
data, people who works in the entertainment industry still have the lowest risk of
being overweight and obese. However, mining and agriculture have the highest risk of
being obese, while public administration, education, trade, finance and other service
become the moderate risk of being overweight and obese. The reason for that might
be due to the fact that in mining and agriculture industries, people require more
physical activity during the work time; therefore, at the leisure time those people will
be less likely to maintain their physical activity. Compared to the CCHS data, the
NPHS cross-section data use a different time period and sample size, which might
cause the results to differ. For the NPHS panel data, the results are quite different
from those from the CCHS and NPHS cross-sectional data, which might relate to an
insufficient sample size.
Comparing the regression results, people who work in occupation 1 and
occupation 3 have a higher risk to become obese, whereas people who work in
occupation 2 and occupation 4 are less likely to be obese. This could because the
category has too many different job classifications. The significant factor which could
affect BMI in occupation 1 and occupation 3 is sedentary time. Household income
correlates to occupation. For example, people who fall under the category of
occupation 2 have middle household income which contributes to the lowest risk of
50
being obese. However, the occupation 4 includes trade, transportation, manufacturing
and agriculture that require lots of physical activity.
Table 10: Rank of industry and work occupation based on BMI3
(for
overweight)
Industry
CCHS with HB NPHS with HB Panel with HB
Public administration Other service Agriculture
Education Manufacturing Finance
Trade Public administration Manufacturing
Finance Agriculture Other service
Mining Education Education
other service Mining Public administration
Entertainment Finance Trade
Manufacturing Trade Mining
Agriculture Entertainment Entertainment
Occupation
occupation 4 occupation 1 occupation 2
occupation 1 occupation 3 occupation 3
occupation 3 occupation 4 occupation 1
occupation 2 occupation 2 occupation 4
Note: 1, HB= human behavior.
2, the explanation of the work occupation category shows on the methodology part.
Table 11: Rank of industry and work occupation based on BMI4 (for obesity)
Industry
CCHS with HB NPHS with HB Panel with HB
Public administration Mining Finance
Education Agriculture Manufacturing
Mining Public administration Other service
Trade Trade Trade
Finance Education Entertainment
Other service Other service Mining
Manufacturing Finance Education
3 Occupation 1 contains managers; Occupation 2 includes business, finance and administration occupations,
natural and applied sciences and elated occupations, health and education occupations; Occupation 3 consists of middle management in retail, sales and service; Occupation 4 included middle management in transportations, agriculture and manufacturing. 4 Occupation 1 contains managers; Occupation 2 includes business, finance and administration occupations,
natural and applied sciences and elated occupations, health and education occupations; Occupation 3 consists of middle management in retail, sales and service; Occupation 4 included middle management in transportations, agriculture and manufacturing.
51
Agriculture Manufacturing Agriculture
Entertainment Entertainment Public administration
Occupation
occupation 1 occupation 3 occupation 3
occupation 3 occupation 1 occupation 1
occupation 4 occupation 4 occupation 2
occupation 2 occupation 2 occupation 4
Note: 1, HB= human behavior.
2, the explanation of the work occupation category shows on the methodology part.
VI Conclusion
This report assesses the existence and strength of the potential relationship between
industries, work occupations, and body weight. To do so, CCHS and NPHS data have
been used to do the estimation separately. Logit regression and fixed effect logit
regressions are run to determine which industries and work occupations will have the
higher risk of being overweight and obese. Also, many correlated variables have been
added to the estimation regression based on the literature and information available in
the data.
BMI has been selected to identify whether people are normal weight, overweight
or obese. The samples have been categorized based on the WHO and Health Canada
body mass index classification systems. Four steps of regression estimation have been
utilized to process the results. First, I used age, gender, province, and education as
independent variables for the base model, and then I added the household income at
second step, the industry in the third step and work occupation variables and human
behaviors variables in the last step. In addition, I restricted the age of respondents
from 25 to 65 as these people are likely to be employed. Hence total number of CCHS
52
respondents is 274,351 in the first regression and 186,967 in the fourth step. For the
NPHS (Cycle 5), there were 6267 respondents at beginning and 3680 left. For the
NPHS panel database, a total of 14,080 individuals are included in the first regression,
while only 2226 respondents are left in the last regression.
The regressions indicates that compared to females, males are more likely to be
overweight and obese, which is contrary to some literatures that female have higher
risk of being overweight and obese for Canada. This could due to different variables
included in my models; also, there are factors like human behaviors which might
correlate with gender. The results for the age variable that with aging people will
suffer higher risk of being overweight and obese are what I had expected. For the
province variable, perhaps due to insufficient NPHS data to do the estimation, there
are some differences between the outcome of CCHS and NPHS, but still in general,
provinces with higher GDP will have lower risk of being overweight and obese.
Overall, the tendency of education results are quite similar to other researchers’ results,
with higher education level, people have better body weight control. The exceptions
are when people obtained highest education in the trade certificate and college level;
they have bigger risk to become obese. This might due to some correlated variables
are added in my regression like household income, occupation and human behavior.
Higher income contributes to higher BMI, which is in contrast to most studies
and the result is inconclusive. Results from human behavior variable (eating habits,
drink type, stress at work and physical activity) suggest that undertaking physical
activity during leisure time, eating healthy food and less work stress will benefit
53
people’s body mass index. However, the regression results on this are not consistent
between using CCHS and NPHS data. This might due to the different period of time I
choose and insufficient observations in NPHS panel data.
The main results from CCHS data show: People who work at public
administration and education industry have highest risk to become obese; people who
work at mining, trade, finance, other service and manufacturing industries have
moderate risk to become obese; only people involved in entertainment industry are
less likelihood of obesity and overweight. On the other hand, results from NPHS data
show a different story: people choose to work at mining and agriculture industries are
more likely to become obese; people in entertainment industry have lowest risk to
become obese; other industries are in the middle range. The last data set, NPHS panel
data, contains contrary results compare to NPHS cross-sectional data and there is little
pattern in it. Occupation 1 and 3 contribute most to people’s risk of being obese cross
all three data sets. People in occupations 2 and 4 have smaller chances of being obese.
My results are different from past Canadian studies; the likely main reason is we have
different categories on industry and occupation. Most Canadian studies classify
industries and occupations by how much physical activity involve in people’s daily
work, so there are two occupations left, blue collar and white collar. According to
their studies, blue collar suffers higher risk to become obese compared to white collar.
In my study, all industries and occupations are sorted by professional skills according
to North American Industry Classification System (NAICS) and National
Occupational Classification (NOC).
54
Compared to other’s work, there are limitations in my work. The first limitation
is data. In my report I have used two databases CCHS and NPHS. For both data sets,
most of the answers in these surveys are simply yes or no. Moreover, due to the
serious attrition rates, almost half of respondents omitted at the end of the NPHS
cycle.
In my study I only focus on how industries and work occupations will influence
people’s body weight. However, people’s body weight could also limit their career; I
didn’t test the correlation from this side. Finally, I classified the industry and work
occupation according to the professional skills. There are many factors could
influence people’s body weight, and many of them can’t be observed from my
original data.
As I mentioned before, even though my research filled some research gaps, there are
remains blank space for further research.
55
Table 4; Logit model based on overweight as outcome (CCHS, 2007-2014)
Dependent variable=overweight
Base
model
Control household income Control industry and
occupation
Control Human Behavior
Variables OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es
Female
0.81899
92
-0.29687
77 ***
0.8221
1
-0.195
88 ***
0.7864
6
-0.240
21 ***
0.7431
35
-0.296
88 ***
Age
1.01295
5
0.01066
24 ***
1.0129
83
0.0128
99 ***
1.0120
62
0.0119
89 ***
1.0107
19
0.0106
62 ***
Urban 0.89960
96
-0.14125
87 ***
0.8939
79
-0.112
07 ***
0.8763
44 -0.132 ***
0.8682
65
-0.141
26 ***
Province
P.E.I
0.85545
26
-0.18823
87 ***
0.8551
09
-0.156
53 ***
0.8629
97
-0.147
34 ***
0.8284
17
-0.188
24 ***
NS
0.91076
27
-0.13943
57 ***
0.9071
71
-0.097
42 ***
0.8860
35 -0.121 ***
0.8698
49
-0.139
44 ***
NB
0.91890
13
-0.14360
96 ***
0.9092
6
-0.095
12 ***
0.8917
1
-0.114
61 ***
0.8662
26
-0.143
61 ***
Quebec
0.54372
17
-0.60223
29 ***
0.5443
37
-0.608
19 ***
0.5315
31
-0.631
99 ***
0.5475
88
-0.602
23 ***
ON
0.64321
12
-0.47621
01 ***
0.6385
25
-0.448
59 ***
0.6280
88
-0.465
07 ***
0.6211
33
-0.476
21 ***
Manitoba
0.80183
71
-0.26972
76 ***
0.8000
72
-0.223
05 ***
0.7743
94
-0.255
67 ***
0.7635
87
-0.269
73 ***
Saskatchewan 0.88287 -0.17121 *** 0.8776 -0.130 *** 0.8472 -0.165 *** 0.8426 -0.171 ***
56
26 56 38 52 8 72 4 22
Alberta
0.68410
63
-0.38283
79 ***
0.6804
35
-0.385
02 ***
0.6797
35
-0.386
05 ***
0.6819
23
-0.382
84 ***
BC
0.46053
24
-0.75886
25 ***
0.4624
97
-0.771
12 ***
0.4674
32
-0.760
5 ***
0.4681
99
-0.758
86 ***
Yukon
0.65964
64
-0.40084
19 ***
0.6555
01
-0.422
36 ***
0.6469
42
-0.435
5 ***
0.6697
56
-0.400
84 ***
NT
0.99733
07
-0.00565
56 0.642
0.9995
42
-0.000
46 0.937
0.9590
32
-0.041
83 ***
0.9943
6
-0.005
66 ***
Nunavut
1.03810
5
0.14989
47 ***
1.0333
68
0.0328
24 ***
1.0929
17
0.0888
5 ***
1.1617
12
0.1498
95 ***
Education
Grade 9-13
0.99429
83
#VALU
E! ***
1.0090
41 0.009 ***
1.0117
78
0.0117
09 ***
1.0234
12
0.0231
43 ***
secondary 0.92198
74
-0.08122
37 ***
0.9527
77
-0.048
37 ***
1.0163
66
0.0162
33 ***
1.0414
85
0.0406
48 ***
trades CER 0.93073
21
-0.07178
38 ***
0.9588
65
-0.042
01 ***
1.0092
13
0.0091
71 ***
1.0243
42
0.0240
51 ***
College
0.89335
52
-0.11277
1 ***
0.9205
21
-0.082
82 ***
0.9821
58 -0.018 ***
0.9974
29
-0.002
57 0.462
below bachelor
0.72508
58
-0.32146
53 ***
0.7505
36
-0.286
97 ***
0.8108
29
-0.209
7 ***
0.8245
15
-0.192
96 ***
bachelor degree
0.58914
18
-0.52908
83 ***
0.6065
66
-0.499
94 ***
0.6454
68
-0.437
78 ***
0.6525
66
-0.426
84 ***
Univ, and above
0.42417
72
-0.85760
4 ***
0.4364
48
-0.829
09 ***
0.4532
52
-0.791
31 ***
0.4632
85
-0.769
41 ***
57
Income
<5k
1.1123
48
0.1064
73 ***
0.7329
78
-0.310
64 ***
0.7055
15
-0.348
83 ***
5k-9.99k
1.2999
98
0.2623
63 ***
0.8015
32
-0.221
23 ***
0.7968
82
-0.227
05 ***
10k-14.999k
1.4562
71
0.3758
79 ***
1.1055
14
0.1003
1 ***
1.1581
41
0.1468
16 ***
15k-19.999k
1.3683
34
0.3135
94 ***
0.9035
14
-0.101
46 ***
0.9003
87
-0.104
93 ***
20k-29.999k
1.2854
91
0.2511
41 ***
0.8978
43
-0.107
76 ***
0.8684
48
-0.141
05 ***
30k-39.999k
1.1903
82
0.1742
75 ***
0.9181
13
-0.085
43 ***
0.8931
95
-0.112
95 ***
40k-49.999k
1.1877
78
0.1720
84 ***
0.9437
62
-0.057
88 ***
0.9166
82
-0.086
99 ***
50k-59.999k
1.1661
25
0.1536
87 ***
0.9523
44
-0.048
83 ***
0.9331
84
-0.069
15 ***
60k-79.999k
1.2531
84
0.2256
87 ***
1.0091
4
0.0090
99 0.389 0.9833
-0.016
84 0.119
80k-99.999k
1.2935
96
0.2574
26 ***
1.0552
38
0.0537
66 ***
1.0375
45
0.0368
58 ***
>100k
1.2433
84
0.2178
37 ***
1.0238
33
0.0235
53 0.026
1.0174
04
0.0172
54 0.11
Industry
Mining, Construction
1.1326
96
0.1246
01 ***
1.1717
2
0.1584
73 ***
58
Manufacturing
1.0077
79
0.0077
49 ***
1.0056
96
0.0056
8 ***
Whole, retail TRD
1.2859
48
0.2514
96 ***
1.2719
49
0.2405
5 ***
Finance and
Insurance
1.2144
73
0.1943
1 ***
1.2140
21
0.1939
38 ***
Educational, Health
1.3461
04
0.2972
15 ***
1.3632
43
0.3098
66 ***
Entertainment
1.1087
91
0.1032
7 ***
1.1332
16
0.1250
6 ***
Other Services
1.1521
59
0.1416
38 ***
1.1543
99
0.1435
8 ***
Public
Administration
1.3595
4
0.3071
46 ***
1.3875
33
0.3275
28 ***
Occupation
Occupation 2
0.9408
49
-0.060
97 ***
0.9560
75
-0.044
92 ***
Occupation 3
0.9434
17
-0.058
25 ***
0.9781
5
-0.022
09 ***
Occupation 4
1.0108
25
0.0107
67 ***
1.0398
94
0.0391
19 ***
Drink fruit
per week
1.1881
75
0.1724
18 ***
per month
1.2892
97
0.2540
97 ***
59
per year
1.4613
84
0.3793
84 ***
never
1.3305
63
0.2856
02 ***
Eat fruit
per week
1.1466
48
0.1368
43 ***
per month
1.2366
65
0.2124
18 ***
per year
1.0595
98
0.0578
89 ***
never
1.0988
07
0.0942
25 ***
Eat carrots
per week
1.0375
11
0.0368
25 ***
per month
1.0641
25
0.0621
53 ***
per year
1.0773
29
0.0744
85 ***
never
1.2173
66
0.1966
89 ***
Eat other vegetable
per week
1.0616
79
0.0598
51 ***
per month
1.1352 0.1268 ***
60
14 21
per year
1.2807
7
0.2474
62 ***
never
1.2321
72
0.2087
79 ***
PC (leisure time)
no
1.3906
22
0.3297
52 ***
Smoke type
occasionally
1.1109
02
0.1051
73 ***
not at all
1.4493
74
0.3711
32 ***
Drink type
occasionally
1.5121
01 0.4135 ***
not at all
1.1149
64
0.1088
22 ***
Stress of work
Not very
1.0030
29
0.0030
24 ***
A bit
1.0634
94
0.0615
6 ***
Quite a bit
1.2042
22
0.1858
34 ***
Extremely
1.4550 0.3750 ***
61
61 48
NO of observations 274351
26773
6
19365
1
18696
7
Note: *** statistically significant at the 1% level
Table 5, Logit model based on obesity as outcome (CCHS, 2007-2014).
Dependent variable=obesity
Base
model Control household income Control industry and
occupation
Control Human Behavior
Variables OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es
Female
0.4547
65
-0.7879
8 ***
0.4611
16
-0.7741
1 ***
0.4308
81
-0.8419
2 ***
0.4161
95 -0.8766 ***
Age
0.0228
28
1.0230
91 ***
1.0231
4
0.0228
76 ***
1.0228
72
0.0226
14 ***
1.0223
11
0.0220
66 ***
Urban 0.8945
52
-0.1114
3 ***
0.9021
39
-0.1029
9 ***
0.8946
76
-0.1112
9 ***
0.8871
56
-0.1197
3 ***
Province
P.E.I
0.7216
82
-0.3261
7 ***
0.7302
81
-0.3143
3 ***
0.7347
74
-0.3081
9 ***
0.7062
04
-0.3478
5 ***
NS
0.8148
83
-0.2047
1 ***
0.8240
55
-0.1935
2 ***
0.8126
88
-0.2074
1 ***
0.7959
57
-0.2282
1 ***
NB
0.8363
93
-0.1786
6 ***
0.8340
84
-0.1814
2 ***
0.8118
06
-0.2084
9 ***
0.7933
51
-0.2314
9 ***
62
Quebec
0.5092
74
-0.6747
7 ***
0.5108
91 -0.6716 ***
0.5043
09
-0.6845
7 ***
0.5023
63
-0.6884
3 ***
ON
0.5988
32
-0.5127
8 ***
0.5886
79
-0.5298
7 ***
0.5857
8
-0.5348
1 ***
0.5700
89
-0.5619
6 ***
Manitoba
0.7506
61 -0.2868 ***
0.7375
08
-0.3044
8 ***
0.7293
59
-0.3155
9 ***
0.7039
97
-0.3509
8 ***
Saskatchewan
0.7956
29
-0.2286
2 ***
0.7742
28
-0.2558
9 ***
0.7602
61
-0.2740
9 ***
0.7474
1
-0.2911
4 ***
Alberta
0.6363
49
-0.4520
1 ***
0.6097
17
-0.4947
6 ***
0.5947
25
-0.5196
6 ***
0.5774
95
-0.5490
5 ***
BC
0.4313
92
-0.8407
4 ***
0.4267
97
-0.8514
5 ***
0.4329
14
-0.8372
2 ***
0.4212
68
-0.8644
9 ***
Yukon
0.5856
12 -0.5351 ***
0.5768
28
-0.5502
1 ***
0.5489
36
-0.5997
7 ***
0.5535
62
-0.5913
8 ***
NT
0.9014
53
-0.1037
5 ***
0.8833
73
-0.1240
1 ***
0.8873
98
-0.1194
6 ***
0.9017
4
-0.1034
3 ***
Nunavut
0.7552
66
-0.2806
9 ***
0.7346
04
-0.3084
2 ***
0.8206
46
-0.1976
6 ***
0.9081
43
-0.0963
5 ***
Education
Grade 9-13
0.9556
75
-0.0453
4 ***
0.9286
83
-0.0739
9 ***
1.0849
37
0.0815
22 ***
1.1002
75
0.0955
6 ***
secondary 0.9996
94
-0.0003
1 0.867
0.9252
92
-0.0776
5 ***
1.1020
19
0.0971
44 ***
1.1102
39
0.1045
76 ***
trades CER 1.0516
4
0.0503
51 ***
0.9530
67
-0.0480
7 ***
1.1377
78
0.1290
77 ***
1.1371
86
0.1285
57 ***
College 1.0737 0.0711 *** 0.9517 -0.0494 *** 1.1470 0.1371 *** 1.1350 0.1266 ***
63
09 19 5 5 47 91 67 91
below bachelor
0.8905
82
-0.1158
8 ***
0.7717
09
-0.2591
5 ***
0.9649
3 -0.0357 ***
0.9550
3
-0.0460
1 ***
bachelor degree
0.7417
29
-0.2987
7 ***
0.6379
62
-0.4494
8 ***
0.7843
06
-0.2429
6 ***
0.7617
97
-0.2720
7 ***
Univ, and above
0.5739
95
-0.5551
3 ***
0.4858
66
-0.7218
2 ***
0.5951
42
-0.5189
6 ***
0.5820
36
-0.5412
2 ***
Income
<5k
1.3253
98
0.2817
13 ***
0.7903
57
-0.2352
7 ***
0.7891
73
-0.2367
7 ***
5k-9.99k
1.2335
45
0.2098
92 ***
0.7742
57
-0.2558
5 ***
0.7902
67
-0.2353
8 ***
10k-14.999k
1.4129
76
0.3456
98 ***
0.7367
26
-0.3055
4 ***
0.7601
32
-0.2742
6 ***
15k-19.999k
1.4367
12
0.3623
57 ***
0.7121
07
-0.3395
3 ***
0.7248
1
-0.3218
5 ***
20k-29.999k
1.3108
86
0.2707
03 ***
0.6689
88
-0.4019
9 ***
0.6564
1
-0.4209
7 ***
30k-39.999k
1.4057
25
0.3405
53 ***
0.7498
19
-0.2879
2 ***
0.7378
86
-0.3039
7 ***
40k-49.999k
1.4771
62
0.3901
23 ***
0.7980
09
-0.2256
4 ***
0.7741
27
-0.2560
2 ***
50k-59.999k
1.4311
72
0.3584
94 ***
0.7887
13
-0.2373
5 ***
0.7734
36
-0.2569
1 ***
60k-79.999k
1.6141
9
0.4788
33 ***
0.8830
56
-0.1243
7 ***
0.8629
98
-0.1473
4 ***
64
80k-99.999k
1.7497
88
0.5594
95 ***
0.9707
2
-0.0297
2 ***
0.9536
22
-0.0474
9 ***
>100k
1.7313
58
0.5489
06 ***
0.9492
9
-0.0520
4 ***
0.9268
87
-0.0759
2 ***
Industry
Mining, Construction
1.1302
1
0.1224
03 ***
1.1731
97
0.1597
33 ***
Manufacturing
1.0345
93
0.0340
08 ***
1.0454
45
0.0444
43 ***
Whole, retail TRD
1.1488
2
0.1387
35 ***
1.1496
98
0.1394
99 ***
Finance and Insurance
1.1106
03
0.1049
03 ***
1.1162
21
0.1099
49 ***
Educational, Health
1.1797
93
0.1653
39 ***
1.1821
19
0.1673
09 ***
Entertainment
0.9656
26
-0.0349
8 ***
0.9995
4
-0.0004
6 0.808
Other Services
1.0533
11
0.0519
38 ***
1.0599
2
0.0581
93 ***
Public Administration
1.3065
37
0.2673
8 ***
1.3145
98
0.2735
31 ***
Occupation
Occupation 2
0.8808
15
-0.1269
1 ***
0.8866
12
-0.1203
5 ***
Occupation 3
0.9641
66
-0.0364
9 ***
0.9910
39 -0.009 ***
65
Occupation 4
0.9473
26
-0.0541
1 ***
0.9802
86
-0.0199
1 ***
Drink fruit juice
per week
1.1138
76
0.1078
46 ***
per month
1.2495
24
0.2227
63 ***
per year
1.2481
41
0.2216
55 ***
never
1.1671
79
0.1545
9 ***
Eat fruit
per week
1.1344
63
0.1261
6 ***
per month
1.1270
6
0.1196
12 ***
per year
0.9749
26
-0.0253
9 ***
never
1.0690
57
0.0667
77 ***
Eat carrots
per week
1.0068
31
0.0068
08 ***
per month
0.9828
29
-0.0173
2 ***
per year
1.1325 0.1244 ***
66
29 53
never
1.1960
9
0.1790
58 ***
Eat other vegetable
per week
1.1178
74
0.1114
29 ***
per month
1.2488
16
0.2221
96 ***
per year
1.0460
91
0.0450
6 ***
never
1.0995
14
0.0948
68 ***
PC (leisure time)
no
1.1663
16
0.1538
5 ***
Smoke type
occasionally
1.2881
0.2531
68 ***
not at all
1.4581
31
0.3771
56 ***
Drink type
occasionally
1.2944
85
0.2581
13 ***
not at all
1.0928
58
0.0887
96 ***
Stress of work
67
Not very
1.0009
09
0.0009
09 0.333
A bit
1.0757
98
0.0730
63 ***
Quite a bit
1.1876
63
0.1719
88 ***
Extremely
1.2948
13
0.2583
67 ***
NO of observations 274351
267736
193651
186967
Note: *** Statistically significant at 1% level
Table 6, Logit model based on overweight as outcome (NPHS, cycle 5).
Dependent variable=Overweight
Base
model
Control household income Control industry and
occupation
Control Human Behavior
Variables OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es
Female
0.40327
1
-0.9081
5 ***
0.40631
3
-0.9006
3 ***
0.40603
8
-0.9013
1 *** 0.30173
-1.1982
2 ***
Age
1.03127
1
0.03079
2 ***
1.03056
6
0.03010
8 ***
1.02696
3
0.02660
6 ***
1.03098
4
0.03051
4 ***
Province
PEI 1.06150 0.05968 *** 1.05013 0.04891 *** 1.05551 0.05402 *** 1.19679 0.17964 ***
68
6 9 3 7 2 6 3
NS
0.77838
3
-0.2505
4 ***
0.79917
4
-0.2241
8 ***
0.71660
5
-0.3332
3 ***
0.52654
5
-0.6414
2 ***
NB
1.01627
2
0.01614
2 0.02
0.97306
9 -0.0273 ***
0.93379
4 -0.0685 ***
0.93697
2 -0.0651 ***
QUE
0.48516
2
-0.7232
7 ***
0.47918
7
-0.7356
6 *** 0.47886
-0.7363
5 *** 0.46631
-0.7629
1 ***
ONT
0.64740
7
-0.4347
8 ***
0.64235
7
-0.4426
1 ***
0.59685
8
-0.5160
8 *** 0.60892
-0.4960
7 ***
MAN 0.70694
-0.3468
1 ***
0.68446
3
-0.3791
2 ***
0.69455
4
-0.3644
9 ***
0.67315
3
-0.3957
8 ***
SASK
0.87135
3
-0.1377
1 ***
0.84856
5
-0.1642
1 ***
0.80983
6
-0.2109
2 ***
0.81050
1 -0.2101 ***
ALTA
0.80954
3
-0.2112
9 ***
0.74794
7
-0.2904
2 ***
0.78715
1
-0.2393
4 ***
0.79034
6
-0.2352
8 ***
BC
0.57263
7 -0.5575 ***
0.56675
4
-0.5678
3 ***
0.56500
9
-0.5709
1 ***
0.55717
9
-0.5848
7 ***
YUKON 1 0
1 0
1 0
NT 7.29204
1.98678
3 ***
7.23709
6 1.97922 ***
6.75662
4
1.91052
3 *** 1 0
NUNAVUT 1 0
1 0
1 0
0.49888
7 0
UNITED STATES
0.64128
8
-0.4442
8 ***
0.64457
3
-0.4391
7 ***
0.61302
6
-0.4893
5 ***
-0.6953
8 ***
Education
Secondary 0.97839 -0.0218 *** 1.00127 0.00127 0.837 1.14858 0.13853 *** 0.35812 -1.0268 ***
69
9 4 2 2 4 1 9
College
0.95457
3
-0.0464
9 ***
0.94831
3
-0.0530
7 ***
1.09434
7
0.09015
8 ***
0.32426
1
-1.1262
1 ***
University
0.81258
8
-0.2075
3 ***
0.83411
8
-0.1813
8 ***
0.95319
9
-0.0479
3 ***
0.26739
4
-1.3190
3 ***
Dipl
0.92350
8
-0.0795
8 *** 0.91502
-0.0888
1 ***
1.01966
6
0.01947
5 0.008
0.29049
3
-1.2361
7 ***
Bachelor
0.69445
1
-0.3646
3 ***
0.69278
8
-0.3670
3 ***
0.78473
4
-0.2424
1 ***
0.24024
3
-1.4261
1 ***
Above master
0.44605
9 -0.8073 ***
0.45020
6
-0.7980
5 ***
0.50971
8 -0.6739 ***
0.12948
4 -2.0442 ***
Income
5k-9.99k
0.82274
2
-0.1951
1 ***
0.35400
4
-1.0384
5 ***
0.24586
6
-1.4029
7 ***
10k-14.999k
2.03870
1
0.71231
3 ***
1.30937
5 0.26955 ***
0.83936
4
-0.1751
1 ***
15k-19.999k
1.69926
6
0.53019
6 ***
0.83661
7
-0.1783
9 ***
0.65033
9
-0.4302
6 ***
20k-29.999k
1.28007
1
0.24691
6 ***
0.77575
2
-0.2539
2 ***
0.46066
6
-0.7750
8 ***
30k-39.999k
1.48827
8 0.39762 ***
0.87917
2
-0.1287
7 ***
0.58509
9
-0.5359
7 ***
40k-49.999k
1.74344
3
0.55586
2 ***
1.10897
9 0.10344 ***
0.63249
9
-0.4580
8 ***
50k-59.999k
1.76162
0.56623
4 ***
1.05719
1
0.05561
6 ***
0.68544
7
-0.3776
8 ***
70
60k-79.999k
1.96747
9
0.67675
3 *** 1.23948
0.21469
2 ***
0.79214
2
-0.2330
1 ***
>=80k
1.55677
8
0.44261
8 ***
0.98344
5
-0.0166
9 0.182
0.63893
6
-0.4479
5 ***
Industry
Mining, Construction
0.85358
7
-0.1583
1 ***
0.95757
5
-0.0433
5 ***
Manufacturing
0.95518
9
-0.0458
5 ***
1.00507
9
0.00506
6 0.413
Whole, retail TRD
0.81530
4
-0.2041
9 ***
0.86827
6
-0.1412
5 ***
Finance and Insurance
0.80923
4
-0.2116
7 ***
0.88890
6
-0.1177
6 ***
Educational, Health
0.89899
7
-0.1064
8 *** 0.96131
-0.0394
6 ***
Entertainment
0.66154
1
-0.4131
8 ***
0.83063
7
-0.1855
6 ***
Other Services
0.88400
2 -0.1233 ***
1.16298
9
0.15099
4 ***
Public Administration
0.94077
9
-0.0610
5 *** 1.00396
0.00395
2 0.57
Occupation
Occupation 2
0.75922
5
-0.2754
6 ***
0.68849
5
-0.3732
5 ***
Occupation 3
0.98069
7
-0.0194
9 ***
0.91207
5
-0.0920
3 ***
71
Occupation 4
0.75390
1
-0.2824
9 ***
0.70124
2 -0.3549 ***
Drink fruit juice
per week
1.20058
0.18280
4 ***
per month
1.20290
6 0.18474 ***
per year
3.79190
2
1.33286
8 ***
Eat fruit
per week
1.04285
2 0.04196 ***
per month
0.94981
5
-0.0514
9 ***
per year
2.70707
7 0.99587 ***
Eat carrots
per week
1.07544
1 0.07273 ***
per month
1.13969
4 0.13076 ***
per year
0.60838
1
-0.4969
5 ***
Eat other vegetable
per weekly
0.75389
2
-0.2825
1 ***
72
per month
0.85035
9 -0.1621 ***
per year
0.93391
2
-0.0683
7 ***
PC (leisure time)
no
1.33023
8
0.28535
8 ***
Stress (work)
Agree
1.38644
1 0.32674 ***
disagree
1.19086
7
0.17468
2 ***
Strong Disagree
1.11156
9
0.10577
3 ***
Job satisfaction
Some
1.08068
9
0.07759
9 ***
Not too
1.25801
7
0.22953
7 ***
Not at all
1.30767
9
0.26825
4 ***
Drink type
weekly
0.63410
3
-0.4555
4 ***
dailly
0.54342
1
-0.6098
7 ***
73
NO of observations 6267
5925
5293
3680
Note: *** Statistically significant at 1% level
Table 7, Logit model based on obesity as dependent variable (NPHS, cycle 5).
Dependent variable=Obesity
Base
model
Control household income Control industry and
occupation
Control Human Behavior
Variables OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es OR Coef.
P-valu
es
Female
0.90086
7 -0.1044 ***
0.88443
3
-0.1228
1 ***
0.88456
1
-0.1226
6 ***
0.74503
9
-0.2943
2 ***
Age
1.00917
7
0.00913
5 ***
1.00983
7
0.00978
9 ***
1.00736
6
0.00733
9 ***
1.00205
5
0.00205
3 ***
Province
PEI
0.72464
9
-0.3220
7 ***
0.73519
8
-0.3076
2 ***
0.73339
5
-0.3100
7 ***
0.90747
7
-0.0970
9 ***
NS
0.85995
8
-0.1508
7 ***
0.84407
3
-0.1695
2 ***
0.86924
3
-0.1401
3 ***
0.67507
5
-0.3929
3 ***
NB
1.32059
7
0.27808
4 ***
1.36042
6
0.30779
8 ***
1.43771
5
0.36305
5 *** 1.82219
0.60003
9 ***
QUE
0.53409
8
-0.6271
8 ***
0.54603
6
-0.6050
7 ***
0.56695
5
-0.5674
8 ***
0.76919
9
-0.2624
1 ***
ONT
0.80802
9
-0.2131
6 ***
0.83912
1 -0.1754 ***
0.87026
8
-0.1389
5 ***
1.05875
2
0.05709
1 ***
74
MAN 1.01037
0.01031
7 0.115
1.00861
5
0.00857
8 0.2
1.06358
2
0.06164
3 ***
1.62037
9 0.48266 ***
SASK
1.23028
8
0.20724
9 ***
1.24572
3
0.21971
6 ***
1.29112
3
0.25551
3 ***
1.98282
6
0.68452
3 ***
ALTA
0.79640
5
-0.2276
5 ***
0.82598
1
-0.1911
8 ***
0.84389
7
-0.1697
2 ***
1.00178
3
0.00178
1 0.845
BC
0.66948
9
-0.4012
4 ***
0.67399
5
-0.3945
3 ***
0.67780
5 -0.3889 ***
1.04904
9
0.04788
4 ***
YUKON
NT
23.8211
8
3.17057
5 *** 26.3747
3.27240
5 ***
25.2870
8
3.23029
4 *** 1 0
NUNAVUT 1 0
1 0
1 0
1 0
UNITED STATES
0.37289
4
-0.9864
6 ***
0.44329
1
-0.8135
3 ***
0.57499
5
-0.5533
9 *** 0.89965
-0.1057
5 ***
Education
Secondary
0.78125
5
-0.2468
5 ***
1.03271
1
0.03218
7 ***
0.98127
9 -0.0189 0.019
0.79179
4
-0.2334
5 ***
College 0.79859
-0.2249
1 ***
1.00470
1 0.00469 0.498
1.01031
7
0.01026
4 0.222
0.89539
6
-0.1104
9 ***
University
0.60895
9 -0.496 ***
0.84498
5
-0.1684
4 ***
0.84378
7
-0.1698
6 ***
0.73062
1
-0.3138
6 ***
Dipl 0.62654
-0.4675
4 ***
0.82702
7
-0.1899
2 ***
0.80417
8
-0.2179
3 ***
0.57267
6
-0.5574
4 ***
Bachelor
0.58909
6
-0.5291
7 ***
0.80984
8
-0.2109
1 *** 0.83589
-0.1792
6 ***
0.69220
5
-0.3678
7 ***
Above master 0.2679 -1.3171 *** 0.35242 -1.0429 *** 0.36436 -1.0096 *** 0.31145 -1.1665 ***
75
4 7 1 2 1 5
Income
5k-9.99k
0.39303
1
-0.9338
7 ***
0.09282
9
-2.3769
9 ***
0.01777
3
-4.0300
5 ***
10k-14.999k
0.87594
2
-0.1324
5 ***
0.60591
4
-0.5010
2 ***
0.28572
2
-1.2527
4 ***
15k-19.999k
0.79936
3
-0.2239
4 ***
0.47094
6
-0.7530
1 ***
0.29573
3 -1.2183 ***
20k-29.999k
0.54861
6
-0.6003
6 ***
0.40766
1
-0.8973
2 *** 0.31449 -1.1568 ***
30k-39.999k
0.64096
5
-0.4447
8 ***
0.49138
2
-0.7105
3 ***
0.36969
6
-0.9950
8 ***
40k-49.999k
0.57488
4
-0.5535
9 ***
0.43313
5
-0.8367
1 ***
0.28782
9
-1.2453
9 ***
50k-59.999k
0.48268
7
-0.7283
9 ***
0.36800
3
-0.9996
7 ***
0.22944
3 -1.4721 ***
60k-79.999k
0.60841
3 -0.4969 ***
0.48015
1
-0.7336
5 ***
0.31570
7
-1.1529
4 ***
>=80k
0.49292
4 -0.7074 ***
0.38918
8
-0.9436
9 ***
0.28162
4
-1.2671
8 ***
Industry
Mining, Construction
1.14060
3
0.13155
8 ***
1.36960
3
0.31452
1 ***
Manufacturing
0.62666
3
-0.4673
5 ***
0.58529
1
-0.5356
5 ***
Whole, retail TRD
0.78536 -0.2416 *** 0.82648 -0.1905 ***
76
1 1 8
Finance and Insurance
0.67754
-0.3892
9 ***
0.63555
4
-0.4532
6 ***
Educational, Health
0.79219
9
-0.2329
4 ***
0.81248
7
-0.2076
6 ***
Entertainment
0.53753
4
-0.6207
6 ***
0.56838
7
-0.5649
5 ***
Other Services
0.68959
8
-0.3716
5 ***
0.67916
8
-0.3868
9 ***
Public Administration
0.92163
2
-0.0816
1 ***
0.91080
3
-0.0934
3 ***
Occupation
Occupation 2
0.80993
7 -0.2108 ***
0.64987
7
-0.4309
7 ***
Occupation 3
1.14624
5
0.13649
1 ***
1.02967
5
0.02924
4 ***
Occupation 4
0.79905
9
-0.2243
2 ***
0.66718
5
-0.4046
9 ***
Drink fruit juice
per week
1.24563
9
0.21964
8 ***
per month
1.04476
9
0.04379
5 ***
per year
1.40600
5
0.34075
2 ***
Eat fruit
77
per week
0.82672
4
-0.1902
8 ***
per month
0.92076
3
-0.0825
5 ***
per year
2.92890
7
1.07462
9 ***
Eat carrots
per week
0.87484
2
-0.1118
4 ***
per month
0.70661
0.07105
3 ***
per year
2.15399
0.11818
3 ***
Eat other vegetable
per week
0.87484
2
-0.1337
1 ***
per month
0.70661
-0.3472
8 ***
per year
2.15399
0.76732
2 ***
PC (leisure time)
no
1.93937
2
0.66236
4 ***
Stress (work)
Agree
1.55058
3
0.43863
1 ***
78
disagree
1.22150
7
0.20008
5 ***
Strong Disagree
1.62541
5
0.48576
3 ***
Job satisfaction
Some
1.10511
8
0.09995
2 ***
Not too
1.13770
3
0.12901
1 ***
Not at all
1.17232
3
0.15898
8 ***
Drink type
weekly
0.6177
-0.4817
5 ***
daily
0.78496
2
-0.2421
2 ***
NO of observations 6267
5925
5293
3680
Note: *** Statistically significant at 1% level
Table 8: Fixed effect logit model based on overweight as outcome (NPHS)
Dependent variable=Overweight
Control household income Control Industry Control Occupation Control Human Behavior
Variables OR Coef. P-valu OR Coef. P-valu OR Coef. P-valu OR Coef. P-valu
79
es es es es
Age
1.1801
98
0.1656
82 ***
1.1911
15
0.1748
9 ***
1.1912
14
0.1749
73 ***
1.1401
63
0.1311
71 ***
Income
5k-9.99k
1.2712
43
0.2399
95 ***
1.4505
93
0.3719
73 ***
1.4485
91
0.3705
91 ***
0.7441
67
-0.2954
9 ***
10k-14.999k
1.7199
3
0.5422
84 ***
1.8782
11
0.6303
2 ***
1.8597
6
0.6204
47 ***
0.4898
07
-0.7137
4 ***
15k-19.999k
1.3899
11
0.3292
4 ***
1.8508
97
0.6156
7 ***
1.8673
84
0.6245
39 ***
0.3658
73
-1.0054
7 ***
20k-29.999k
1.3628
82
0.3096
02 ***
1.7569
16
0.5635
6 ***
1.7843
43
0.5790
5 ***
0.4605
3
-0.7753
8 ***
30k-39.999k
1.3999
07
0.3364
06 ***
1.6293
49
0.4881
8 ***
1.6553
42
0.5040
08 ***
0.3272
57
-1.1170
1 ***
40k-49.999k
1.7332
03
0.5499
71 ***
2.0304
57
0.7082
61 ***
2.0792
56
0.7320
1 ***
0.5152
42
-0.6631
2 ***
50k-59.999k
1.5934
91
0.4659
27 ***
1.9963
88
0.6913
4 ***
2.0624
63
0.7239
01 ***
0.5513
48
-0.5953
9 ***
60k-79.999k
2.0030
64
0.6946
78 ***
2.3088
03
0.8367
29 ***
2.3597
27
0.8585
46 ***
0.6653
59
-0.4074
3 ***
>=80k
2.2971
42
0.8316
66 ***
2.6628
82
0.9794
09 ***
2.7185
56
1.0001
01 ***
0.9130
75
-0.0909
4 ***
Industry
Mining, Construction
1.7090
81
0.5359
56 ***
0.4204
11
-0.8665
2 ***
Manufacturing
1.6697 0.5127 ***
0.8065 -0.2149 ***
80
99 03 62 8
Whole, retail TRD
1.3259
96
0.2821
64 ***
0.4472
68 -0.8046 ***
Finance and
Insurance
1.6134
51
0.4783
76 ***
0.9003
91
-0.1049
3 ***
Educational, Health
1.5527
16
0.4400
06 ***
0.5948
48
-0.5194
5 ***
Entertainment
1.2706
84
0.2395
55 ***
0.1594
85
-1.8358
1 ***
Other Services
1.2157
49
0.1953
61 ***
0.6006
41
-0.5097
6 ***
Public Administration
2.0661
96
0.7257
09 ***
0.5662
51
-0.5687
2 ***
Occupation
Occupation 2
1.0184
47
0.0182
79 ***
1.6324
07
0.4900
56 ***
Occupation 3
0.8699
9
-0.1392
7 ***
1.0453
93
0.0443
93 ***
Occupation 4
0.7693
25
-0.2622
4 ***
0.9962
79
-0.0037
3 0.651
Eat potatoes
per week
0.9009
05
-0.1043
6 ***
per month
0.6711
71
-0.3987
3 ***
per year
0.4937 -0.7057 ***
81
62
Eat green salad
per week
1.0550
93
0.0536
29 ***
per month
0.6346
73
-0.4546
4 ***
per year
4.2674
46
1.4510
16 ***
Drink fruit juice
per week
1.0412
18
0.0403
91 ***
per month
1.1315
65
0.1236
01 ***
per year
1.5118
49
0.4133
33 ***
Eat fruit
per week
1.2471
35
0.2208
49 ***
per month
1.1338
7
0.1256
37 ***
per year
0.3654
76
-1.0065
6 ***
Eat carrots
per week
0.9946
8
-0.0053
3 0.2
per month
1.0140 0.0139 ***
82
22 25
per year
0.3087
26 -1.1753 ***
Eat other vegetable
per week
1.1450
47
0.1354
46 ***
per month
1.4393
56
0.3641
96 ***
per year
0.0144
82
-4.2348
7 ***
Physical activity Freq
occasional
1.4670
23
0.3832
35 ***
Infrequent
1.2514
21
0.2242
8 ***
Stress (work)
Agree
0.8356
72
-0.1795
2 ***
disagree
0.9043
83 -0.1005 ***
Strong Disagree
0.7784
58
-0.2504
4 ***
Job satisfaction
Some
1.0069
41
0.0069
18 0.012
Not too
0.5879 -0.5311 ***
83
44 2
Not at all
0.8683
05
-0.1412
1 ***
Drink type
Monthly
1.0181
95
0.0180
32 ***
Weekly
0.9753
43
-0.0249
7 ***
Daily
0.8692
73 -0.1401 ***
NO of Obs 20981
17379
17372
2920
Note: *** Statistically significant at 1% level
Table 9: Fixed effect logit model based on obesity as outcome (NPHS)
Dependent variable=Obesity
Control household income Control Industry Control Occupation Control Human Behavior
Variables OR Coef.
P-value
s OR Coef.
P-value
s OR Coef.
P-value
s OR Coef.
P-value
s
Age
1.18609
7
0.17066
8 ***
1.20003
8
0.18235
3 ***
1.19619
8
0.17914
8 ***
1.23191
5 0.20857 ***
Income
5k-9.99k
0.44574
4
-0.8080
1 ***
0.67007
2
-0.4003
7 ***
0.77489
6
-0.2550
3 ***
0.62534
1
-0.4694
6 ***
10k-14.999k 0.46417 -0.7675 ***
0.60467
8
-0.5030
6 ***
0.61870
8
-0.4801
2 ***
1.43754
8
0.36293
9 ***
84
15k-19.999k
0.43742
7
-0.8268
5 ***
0.52023
4
-0.6534
8 ***
0.55737
8
-0.5845
1 ***
1.25502
9
0.22715
9 ***
20k-29.999k
0.53014
1
-0.6346
1 ***
0.71086
4
-0.3412
7 ***
0.77095
8
-0.2601
2 *** 0.99966
-0.0003
4 0.991
30k-39.999k
0.63227
8
-0.4584
3 ***
0.83684
4
-0.1781
2 ***
0.90492
3
-0.0999
1 ***
1.90408
3
0.64400
1 ***
40k-49.999k
0.64911
3
-0.4321
5 ***
0.74860
2
-0.2895
5 ***
0.82937
8
-0.1870
8 ***
1.74413
6 0.55626 ***
50k-59.999k
0.73302
4
-0.3105
8 ***
0.93046
6
-0.0720
7 *** 1.02478
0.02447
8 0.023
1.61072
5
0.47668
4 ***
60k-79.999k
0.62526
4
-0.4695
8 ***
0.76427
1
-0.2688
3 ***
0.84432
9
-0.1692
1 ***
0.92955
9
-0.0730
4 ***
>=80k
0.80442
6
-0.2176
3 ***
0.99838
8
-0.0016
1 0.881
1.10943
5
0.10385
1 ***
1.55566
7
0.44190
4 ***
Industry
Mining,
Construction
1.10944
6
0.10386
1 ***
1.10099
8
0.09621
7 ***
Manufacturing
1.44515
6
0.36821
7 ***
2.05333
4
0.71946
5 ***
Whole, retail
TRD
1.23997
2
0.21508
9 ***
1.24665
9
0.22046
7 ***
Finance and
Insurance
2.69818
0.99257
8 ***
3.03293
4 1.10953 ***
Educational,
Health
1.93561
9
0.66042
7 ***
1.08473
0.08133
1 ***
Entertainment
1.18018 0.16567 ***
1.21945 0.19840 ***
85
9 5 8 7
Other Services
2.31283
4
0.83847
4 ***
1.42422
9 0.35363 ***
Public
Administration
1.62678
0.48660
3 ***
0.65459
7
-0.4237
4 ***
Occupation
Occupation 2
0.86729
6
-0.1423
8 *** 0.89436
-0.1116
5 ***
Occupation 3
0.90550
7
-0.0992
6 ***
1.05131
5
0.05004
2 ***
Occupation 4
0.59538
2
-0.5185
5 ***
0.29214
2
-1.2305
2 ***
Eat potatoes
per week
0.71414
1
-0.3366
7 ***
per month
0.35253
1
-1.0426
2 ***
per year
0.68517
1
-0.3780
9 ***
Eat green salad
per week
1.70131
7
5.31E-0
1 ***
per month
1.40992
6
0.34353
7 ***
per year
0.16141
9
-1.8237
5 ***
86
Drink fruit juice
per week
1.06309
6
0.06118
5 ***
per month
0.76958
7 -0.2619 ***
per year
0.64002
9
-0.4462
4 ***
Eat fruit
per week
1.01824
2
0.01807
8 ***
per month
1.17070
8
0.15760
9 ***
per year
1.92E+1
0
23.6758
1 0.975
Eat carrots
per week
1.00810
2 0.00807 0.118
per month
1.03952
3
0.03876
2 ***
per year
0.26378
3
-1.3326
3 ***
Eat other
vegetable
per week
1.33485
5
0.28882
2 ***
per month
1.04167 0.04082 ***
87
4 9
per year
8.16E+1
0
25.1245
6 0.985
Physical activity Freq
occasional
1.23997
2
0.21508
9 ***
Infrequent
1.30764
2
0.26822
6 ***
Stress (work)
Agree
1.06467
1
6.27E-0
2 ***
disagree
1.64164
4
0.49569
8 ***
Strong Disagree
2.08873
5
0.73655
9 ***
Job satisfaction
Some
0.93420
3
-0.0680
6 ***
Not too
0.64278
2
-0.4419
5 ***
Not at all
0.75156
8
-0.2855
9 ***
Drink type
Monthly
0.81252
6
-0.2076
1 ***
Weekly
1.05451 0.05308 ***
88
9 4
Daily
2.04984
3
0.71776
3 ***
NO of Obs 14080
11501
11502
2226
Note: *** Statistically significant at 1% level
89
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Appendix
Table 12: 4 groups of work occupation category
Occupation 1 Occupation 2 Occupation 3 Occupation 4
Manager Business Middle management
occupation in
retail and whole
sale trade and
customer service
Middle management
occupations in trades,
transportation,
production and
utilities
Finance
Administration
occupation
Natural and
applied sciences
and related
occupation
Trades, transport and
equipment operators
and related
occupations
Sales and service
occupation
Health
Education
Law and social Natural resources,
agriculture and
related production
occupation
Government service
Art
Culture
Recreation
Sport Occupation in
manufacturing and
utilities
Table 13: 9 groups of industry category
Control group Mining Manufacturing Retail
Agriculture Mining Manufacturing Wholesale trade
Forestry Quarrying
Fishing Oil and gas
extraction
Transportation
Hunting Warehousing
Utilities
Construction
Finance Education Entertainment
Information Education Art Other service
Other service (except
public
administration)
Finance Health care Entertainment
Insurance Social assistance Recreation
Real Estate Accommodation
Scientific Food service
Technical services
Management Public Administration
94
Administrative Public
Administration
Remediation service
Curriculum Vitae
Candidate’s Full Name: Saibiao Peng
University Attended: Bachelor of Economics
Hunan Normal University
Publications: N.A.
Conference Presentations: N.A.