MODERATORS OF CHILDREN’S FOOD LIKING AND INTAKE

Catherine Shehan – November 3, 2014

2Children’s Food Liking and Intake

Children eat what they like and leave the rest.

-L. Birch

• Taste preferences are a primary obstacle to dietary change

• Children innately like the tastes of sweet, salty, and fatty foods

• Children are innately driven to reject bitter and sour tasting foods

• Parents cite disliking as the main barrier to vegetable intake

• Popular Assumptions about children’s liking and intake• Children are assumed to make food choices based solely on taste• Stronger influence of liking on intake for children than adults

“Preschool Children’s Food Preferences And Consumption Patterns” • Leann Birch, 1979 • First direct study of children’s food preferences and intake

• 17 children between aged 3.5 – 5.9• Preference and consumption of 8 types of sandwiches• Strong correlation (r=-.80) found between preference and intake

• Correlation compared to prior results in adults (r=.25 - .50)

Birch, 1979

3

4Methodological Issues• The types of food used in the study

• Foods used in this study included common and novel foods/flavors• Peanut Butter vs. Margarine/Mint Jelly or Cream Cheese/Caviar

Sandwiches• Children’s food choices are driven by food familiarity• Children will reject novel foods without tasting them

• The way intake data were collected• Children selected their sandwiches and ate their meals in groups

of 4-5• Children’s food preferences are affected by social influence• Children mimic their peers’ expressed preferences and eating

behaviors

Birch, 1981, Birch 1982

5

Comparison Issues• Different definitions and measurements of preference were used• Pilgrim and colleagues: 9 Point Hedonic Ratings

• How much do you like A?” • Items may have similar or different ratings

• Birch: Forced Choice Preference Rank Order• “Which do you like better, A or B?”• Each item has a different ranking

• Multiple items can have the same rating, but not the same ranking

Pilgrim et al, 1961; Peryam and Pilgrim, 1957; Hall-Ellis, 1969; Cardello, 1982

6Why revisit food liking and intake?• Birch’s study and results haven’t been replicated• No other studies have looked at preference/liking and total meal

intake • More recent studies have examined categories of foods rather

than meals• Significant relationships found, but not as strong as Birch’s

findings

• Much has since been learned about children’s eating behavior• Identification of influences on children’s food liking and intake• New tools for measuring children’s liking have been developed

•The food environment has changed over the past 35 years

• Children eat more convenience foods and foods away from home• Attitudes toward nutrition and health have shifted • Highly palatable and energy dense foods have become more

popular

Kroll, 1990; Koivisto, 1996 ; Chen, 1996; Cullen, 2003 ;Unusan, 2006 ;Lakkakula, 2011 ;Bouhlal, 2013; Rollins, 2009

7

Energy Density and Food Preference• Energy content per unit of food

• Often expressed in kcal/ g• Ranges from 0 (pure water) to 9 (fat)• Depends on food composition

• Low ED foods are more satiating than high ED foods• 1 Big Mac Combo Meal vs. 18 apples -- both are about 1300 calories

• High ED diets are associated with metabolic syndrome• Children learn to like tastes associated with high ED foods quickly

Birch 1990; Mendoza et al, 2007; Fox, 2006

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Primary Aims• How strong is the relationship between children’s liking and intake of a variety of foods? • Overall food liking and intake are strongly related.• The strength of this relationship differs among individual foods• Liking/Intake relationship differs between High and Low ED

Foods• How do non-hedonic factors affect the relationship between children’s food liking and intake?• The relationship between children’s food liking and intake is

affected by family socioeconomic status• The relationship between children’s food liking and intake is

affected by parental food/nutrition knowledge and behaviors• The relationship between liking and intake is affected by child

age, sex, and BMI percentile

9

Study Design Overview• Cross-sectional design• Children between ages 4-6 and their parents• Two laboratory visits for each participant

• Child Measures• Liking ratings for common and familiar foods/beverages• Intake of these items in a self-selected, ad libitum test meal• Height and weight

• Parent Measures• Socioeconomic Status• Nutrition knowledge• Food/Nutrition related behaviors

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Foods Used in this studyWe chose items that are familiar to most young children.

Tomatoes

Broccoli

Red Grapes

Ketchup

Chicken Nuggets

Cookies

Potato Chips

0 1 2 3 4 5 6 7 8 9Energy Density (kcal/g)

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Liking - Tasting and Rating• Children tasted small samples (1-2 g) of all foods/beverages• Samples were presented in unmarked clear plastic cups• Each item was tasted individually• Children rinsed with spring water between samples

• Ratings collected using 5 Point Smiley Face Scale• Verbal anchors from “Super Bad” “Super Good”• Scripted data collection protocol• Children were trained on using the scale prior to tasting foods

Kroll (1990)

12

Liking - Measures• Conversion to numerical values

• “Super Bad” = 1• “Bad” = 2,• “Maybe Good or Maybe Bad” = 3• “Good” = 4• “Super Good” =5

• Calculation of category and overall liking• Mean ratings for high ED foods, low ED foods, and all foods

• Individual Participant Liking Ratings • Mean of first and second visit ratings for each item/category

• Group Liking Ratings • Mean of individual ratings for each item/category

13Intake - Ad Libitum Test Meal

 Item Serving Size (g)

Broccoli 75 ± 5 Chicken Nuggets 90 ± 5 Cookies 34 ± 3

Fruit Punch 200 ± 5Grapes 75 ± 3 Ketchup 55 ± 5

Milk 200 ± 5Potato Chips 50 ± 5 Tomatoes 75 ± 3

Children were told that they could eat as much or as little of any of the items as they wanted and could ask for additional servings of any food or beverage.

14

Intake Measures• Individual Item Mass (g)

• Each item weighed before and after test meal

• Individual Item Energy (kcal)• Mass multiplied by item energy density

• High Energy Density Food Mass and Energy• Combined intake of chicken nuggets, chips, and cookies

• Low Energy Density Food Mass and Energy• Combined intake of grapes, tomatoes, and broccoli

• Total Mass and Energy• All test meal items, including beverages

• Food Mass, Energy, and Energy Density (kcal/g)• All test meal items except beverages

15

How strong is the association between children’s liking and intake of a variety of common foods?

16

Participants• 58 children* (32 boys, 26 girls)

• Mean age: 5.4 +/- 0.8 years, range 4.0 – 6.9• Mean BMI Percentile: 51.6 +/- 27.7; range 4—99

• 7 children were considered overweight• 3 children were considered obese• 1 child was considered underweight• 1 child refused to be weighed

• Most children (81%) were white and non-Hispanic• 53 mothers and 5 fathers

• Most children had at least one parent with a Bachelor’s degree• Family income ranged from <$20,000/year to >$100,000/year• Nearly half of families participating in this study were income-

eligible for WIC• 27 full-time stay-at-home parents, 31 parents with jobs outside the

home*61 children initially participated in the study, but only 58 children completed both visits

17Liking Ratings

1 2 3 4 5

CookiesPotato ChipsGrapesChicken NuggetsFruit PunchKetchupMilkBroccoliTomatoes

18Test Meal Intake

0 20 40 60 80 100 120

Tomatoes

Chips

Broccoli

Ketchup

Milk

Grapes

Cookies

Chicken Nuggets

Fruit Punch

Intake (g)

19Correlations Between Food Liking and Intake

-1-0.8-0.6-0.4-0.2

00.20.40.60.8

1

Chicken NuggetsCookiesKetchup BroccoliGrapes Milk ChipsFruit PunchTomatoes

Corr

elat

ion

Coeffi

cien

t (rh

o)

20Low ED Foods

1 2 3 4 50

20

40

60

80

100

120

140

160

180

200

Liking

Inta

ke (

g)

Moderate Correlation (rho = 0.28, p=0.03)

21High ED Foods

1 2 3 4 50

50

100

150

200

250

300

Liking

Inta

ke (

g)

Not Significant (rho= -0.03 , p= 0.85)

22

Entire Meal

1 2 3 4 50

100

200

300

400

500

600

700

800

Liking

Inta

ke (g

)

Not significant (rho= -.05 p= 0.72)

23

All Foods

1 2 3 4 50

50

100

150

200

250

300

350

400

450

500

Liking

Inta

ke (g

)

rho = .22, p=.09rho = .19 p=.171 2 3 4 5

0

50

100

150

200

250

300

350

400

450

500

Liking

Inta

ke (g

)

24

Findings – Aim 1•Liking associated with intake of some foods, but not others

• Correlated - chips, grapes, punch, milk, and tomatoes• Not related- chicken nuggets, cookies, broccoli, and ketchup

•Food energy density may affect liking/intake relationship• Low ED food liking and intake were moderately correlated• High ED food liking and intake were not significantly related

•Average liking scores did not predict overall intake

The relationship between children’s food liking and intake may be more complex than previously

thought.

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Part 2: What factors affect the relationship between food liking and intake?

26

Influences on Food Intake

Food Intak

eNutrition Knowles

Nutrition Label

Reading

Home Food Preparation

Socioeconomic Status

Age

Sex

Weight Status

Drewnowski .2003, ; Drewnowski 2004;loth, 2013 ; Misra, 2007; Mcleod, 2011

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INTAKE

LIKING

MODERATOR

MODERATOR * LIKING

Moderation Analysis • Determines how relationships differ between situations

• Linear regression method common in behavioral research• Outcome Variable: Intake• Predictors – Liking, variable of interest, interaction

• Predictors were normalized to meet regression assumptions

• Significant interaction term indicates moderation• Interaction plots used to interpret significant results

Baron and Kenny, 1986

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Potential Moderator

Overall Meal

High ED Foods

Low ED Foods

Nutrition Knowledge ✗ ✗ ✗

Nutrition Label Use ✗ ✗ ✗Food Preparation Time ✗ ✗ ✗

Parental Education ✗ ✗ ✗

Family Income ✗ ✗ ✗Parental Work Status ✗ ✔ ✗

Gender ✗ ✔ ✗Age ✗ ✗ ✗Child BMI Percentile ✗ ✗ ✔ ✔ indicates significant moderation of liking/intake relationship (p < .05) ✗ indicates no significant evidence of moderation

29

Liking and intake of low ED foods were positively related among children who

are overweight/obese but are not related among lower weight children.

-2 0 20

50

100

Liking (z-score)

Inta

ke (g

) Low (n=10)

High (n=10)

BMI Percentile // Low ED Food Liking/Intake

30

Liking and intake of high ED foods were positively correlated among girls

but not among boys.

-2 -1 0 1 20

200

400

600

800

Liking (z-score)

Inta

ke (k

Cal)

Boys (n=32) Girls (n= 26)

Sex // High ED Foods

31

Liking and intake of high ED foods were negatively correlated among

children who have a full-time stay-at-home parent.

-2 -1 0 1 20

100

200

Liking (z-score)

Inta

ke (

g)

Stay-at-Home Parent (n= 27) Employed Parent (n=34)

Work Status // High ED Foods

32

Findings – Aim 2• Some evidence of moderation of liking/intake

• Limited statistical power–low sample size for this type of analysis• Child weight status moderates low ED food liking/intake

• Positive correlation for overweight/obese children but not related in children with lower BMI percentiles

• Sex moderates high ED food liking/intake• Significant positive correlation in girls, but not related among boys

• Parent work status moderates high ED food liking/intake• Significant negative correlation for children with stay-at-home

parents, but not not significant for children with parents working outside the home

33

How does food preparation at home affect children’s test meal food selection?

Part 3

Previously Presented at SSIB 2014

34

Home Food Preparation and Diet Quality• Positive associations found in young adults• Benefits of Food Preparation

• Fewer meals eaten outside the home • Less frequent usage of high ED convenience foods

• Home-cooked meals are usually lower ED than foods prepared away from home

Larson et al. (2006, 2007, 2011;)Larson and Story (2009) food {Morland, 2009Briefel, 2004, St-Onge, 2003)

35

Hypothesis: Time spent by parents on food preparation is negatively associated with the energy density of foods children eat during self-selected ad libitum test meals.

36

Results

MeanStandar

d Deviatio

nMin. Max.

Food Preparation Time (hours)

7.7 4.0 1.0 16.0

Food Energy Density(kCal/g)

2.80 0.62 1.26 4.49

37

0 2 4 6 8 10 12 14 16 180

1

2

3

4

5

Reported Home Food Preparation Time (hours/week)

Ener

gy D

ensit

y (k

Cal/g

)

(r= -.34, p= .01)

Test meal energy density was negatively correlated with reported

food preparation time.

38

Children whose parents reported spending more time on food preparation ate

significantly lower energy density test meals.

A

*One-Way ANOVA and LSD showed significant difference from other groups at p=.015

A

B

F(2,55) = 4.557, p= 0.015

Series10

1

2

3

4

Ene

rgy

Den

sity

(kC

al/g

)

39

-3 -2 -1 0 1 2 30

1

2

3

4

5

SES/PrepTime Residual

Ener

gy D

ensi

ty (k

Cal/g

)

Food preparation time was negatively correlated with with test meal energy density, regardless of

socioeconomic status.

(r= -0.37, p= 0.001)

40

• Part 1• Liking and intake were related in some foods, but not others• Overall liking and intake were not significantly related

• Part 2• Child BMI Percentile moderated Low ED Food Liking/Intake• Parental Work Status and Child Gender moderated High ED food

liking/intake• Part 3

• Reported food preparation time and children’s test meal food energy density were negatively related

• Children whose parents spend 10+ hours on food preparation ate significantly lower energy density test meals than their peers

Summary of findings

41

Limitations• Participant diversity was limited• Participants were not representative of the general population

• Limited number of visits– children’s food intake varies• Unfamiliar eating environment for children• Potential awareness of parental monitoring

• Parents asked not to discuss the study between visits, but….

Birch, 1991Kiesges et al, 1991US Census Bureau, 2014

42

Future Work• Collaborating with other research

groups• Collecting data in less controlled

settings• Conducting interviews and focus

groups• Investigating food preparation in-

depth• Developing and testing

interventions

43

Take-Home Messages• Children don’t just eat what they like and leave the rest

• The relationship between children’s food liking and intake may be influenced by parent and child traits

• The amount of time parents spend on food preparation may influence the quality of children’s food choices away from their parents and their home.

44

Thank you! • Study participants and their families• Kathleen Keller• John Hayes• Josh Lambert• Terri Cravener• Carol Byrd-Bredbenner• Masteneh Sharafi• Friends and family• Ziggydog• Chris Roberson• Alyssa and Axes Chilton• PSU Food Science Department• PSU Nutrition Science Department

Keller Lab

Hayes Lab

46

47Income• Transformed income categories to continuous variable

• Median of each income range

• Per capita income to account for variability in family size• Estimate / # people in household

CategoryEstimated

Gross Income

Per Capita (Family

of 4)

Per Capita(Family

of 8)Less than $20,000

$10,000 $2500 $5000

$20,000 - $35,000

$27,500 $6875 $3475.50

$36,000 - $50,000

$44,000 $11,000 $5500

$51,000 - $75,000

$63,000 $15,750 $7875

$76,000 - $100,000

$88,000 $22,000 $11,000

More than $100,000

$120,000 $30,000 $15,000

48

Acceptance Ratings

49

Test Meal Intake

50

51Children’s liking of foods did not depend on food preparation

time.Low ED Foods

Low Medium High1

2

3

4

5

Food Prep Time

Liki

ng

High ED Foods

Low Medium High1

2

3

4

5

Food Prep Time

Liki

ng

F(2,55)= .314, p= .732 F(2,55)= .492, p= .614

Low = Less than 5 hours/ weekMedium = 5-10 hours/weekHigh = 10 or more hours/week

52Food preparation time is negatively associated with test meal energy density regardless of children’s liking of high/low ED foods.

-8 -6 -4 -2 0 2 4 6 8 100

1

2

3

4

5

f(x) = − 0.0410445549977482 x + 2.79844827586207R² = 0.0598629389728111

Liking/Prep Time Residual

Ener

gy D

ensi

ty (k

Cal/g

).

Food & Nutrition Knowledge

Based on Parmenter & 1999 Wardle’s Nutrition Knowledge Questionnaire

• Adapted for American populations• Kippers & digestive biscuits sardines & graham crackers

Additional Questions Added• True/false questions regarding contemporary food/nutrition concerns• Portion size recognition• Nutrition label reading• Recommendations for children

Score %correct

54

55

56