Abstract

Health Trends in US Adolescents Over the Past 20 YearsSutherland, LA.

Lineberger Comprehensive Cancer Center and Department of Nutrition, University of North Carolina at Chapel Hill

Methods and Procedures

Results

Conclusions

-15

-10

-5

0

5

10

15

1Physical activi ty

-13%

Overweight

+10%

Calor ies +1

Data Sourves:

Physical activity: Youth Behavior Surveillance System (YRBS), CDC, NCCDPHP

Calorie intake: CSFII, USDA

Overweight: National Health and Nutrition Examination Survey II and III, 1999, CDC, NCHS

Program No. 708.7

Abstract: 7714

Over the past twenty years there has been a cornucopia of information presented on the causes and trends in obesity amongst United States adolescents. The goal of this study was to utilize national data sources to compare trends in calorie intake, overweight, and physical activity for US adolescents from 1980-2000. Analyses of data were performed on nationally representative data sets from the United States Department of Agriculture (USDA) for diet and the Centers for Disease Control and Prevention (CDC) for overweight and physical activity of individuals 12-19 years of age. From 1980 to 2000 overweight increased by ten percent, calorie intake has remained fairly constant (+1%), and physical activity declined thirteen percent. Well diet continues to be the primary focus as the cause of obesity in children; the fact is that calorie intake has remained fairly constant, while participation in physical activity has declined according to self-report data from the CDC Youth Risk Behavioral Survey. Given the decrease in physical education in schools, changes in transportation methods, and popularity of TV, video games, and Internet surfing that contribute to the increased sedentary lifestyles kids lead, it is crucial to find new and creative ways to increase physical activity in adolescents as a first line of defense to combating overweight and obesity.

With an increase in the rates of adolescent obesity it is crucial that we gain a better understanding of the factors contributing to this epidemic. While many public policy makers continue to emphasize the role of diet, nevertheless, it is equally important to understand the positive impact increased physical activity may have on this national problem. The goal of this study was to utilize available national data to examine the trends in calorie intake, physical activity and overweight for US adolescents 12-19 years of age.

Physical activity has declined while calorie intake has remained flat for US adolescents

Calorie intake trend is comparable to other well established research findings

Decreased physical activity has an impact on adolescent overweight

Better measures of physical activity for adolescents need to be created and implemented on a national level to improve the level of monitoring

We need to address both sides of the energy equation and strike balance when creating community, state, and federal programs and policy that address childhood obesity

Objectives

Overweight: National Health and Nutrition Examination Survey II, III, and 1999, Centers for Disease Control and Prevention

Cross-sectional nationally representative surveyMeasure: Body Mass Index (BMI)Age-adjusted to 1980 censusSample weightedData analyses with SUDDAN V 8.0

Calorie intake: Nationwide Food Consumption Survey (NFCS), Continuing Survey of Food Intake by Individuals (CSFII), USDA

Cross-sectional nationally representative surveyMeasure: One 24-hr recallAge-adjusted to 1980 censusSample weightedData analyses with SUDDAN V 8.0

Physical activity: Youth Risk Behavioral Survey, CDC.1 Cross-sectional nationally representative surveySelf-report participation in physical education was used as a proxy measure for physical activity.

Introduction Limitations

1. National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Prevention and Control. Youth Risk Behavioral Surveillance System, 2001.

Ogden CL, Flegal KM, Carroll MD, Johnson CL. Prevalence and trends in overweight among US children and adolescent, 1999-2000. JAMA 2002;288:17281732.

Cavadini C, Siega-Riz AM, Popkin BM. US adolescent food intake trends from 1965 to 1996. Arch Dis Child 2000;83:18-24.

Troiano RP, Flegal KM. Overweight children and adolescents: Description, epidemiology, and demographics. Pediatrics 1998;10(3):497-504.

* Examine 20 year trend in caloric intake for adolescents 12-19 years of age

* Review literature and measures for secular trends in physical activity

* Examine the relationship between overweight, caloric intake, and physical

activity over a 20 year period.

References

We utilized three different national data sets

Data collection time points were slightly different for caloric intake, physical activity, and obesity data sets

Some differences exist between the three surveys in sampling and methodology for dietary data collection

Physical activity measure is not a precise measure, but rather a proxy

Snapshot of US adolescent health

Funding for the study was provided by an unrestricted grant from the National Soft Drink Association.