The Impact of a population-level school food nutrition policy on dietary intake and body

weights of Canadian children

Christina Fung, Jessie-Lee D. Mclsaac, Stefan Kuhle, Sara Kirk, Paul J Veugelers

Jennifer M. Holt

Introduction

Interest in Childhood obesity prevention

This article dives into additional population level interventions

Schools play a vital role in population-level obesity intervention.

Appendix Acronyms

CLASS: Children’s Lifestyle and School Performance Study NSNP: Nova Scotia Nutrition Policy YAQ: Harvard Youth Adolescent Food Frequency Questionnaire SSB: sugar sweetened beverages DQI: diet quality index AMDR: Acceptable Micronutrient Distribution EAR: estimated average requirement ND: not determined AI: adequate intake UL: Upper limit

Overweight and obesity rates, by sex, household population aged 2 to 17, Canada (2004) and United States (1999-2002)

Overweight and obesity rates, by sex and age group, household population aged 2 to 17, Canada (2004) and United States (1999-2002)

Background

Childhood obesity is a public health issue

Schools are a vital partner in population-level obesity

In Canada there is no national/federal school nutrition program, provincial/territorial jurisdictions foster these policies.

Question

What would be the pros and cons of having state/territorial/provincial nutrition programs and guidelines as opposed to national/federal?

Methods

CLASS is a province-wide research project that looks at the relationships between health, nutrition, physical activity, mental health and school performance of children in Nova Scotia.

– 2003 (from this NSNP wrote directives)

Post 2003/CLASS I, CLASS II is trying to understand how these changes have influenced children's health and school performance by collecting similar information from students in Grade 5 in 2011

Method

Assess population level trends in children’s nutritional intake and weight status from 2003 to 2011 as impacted by the NSNP directives.

All public schools invited to participate in data collection

NSNP

NSNP: Nova Scotia Nutrition Policy aims to “increase access to and enjoyment of health promoting , safe an affordable food and beverages served and sold in public schools with the objective of helping to make the healthy food and beverage choice the easy choice in the school setting”

Policies

Food and Nutrition Policy for Nova Scotia Public Schools implemented in 2006.

3 categories, 12 directives of NSNP (Nova Scotia Nutrition Policy) Table 2– Nutritional guidelines– Regulation of food and beverages– Price Interventions

Methods

2003- 282/291 schools participated (96.9%)– Of the 282 schools, 5517 parents gave consent resulting in

51.1% of response rate per school.

2011- 269/286 schools participated (94.1%)– Of the 269 schools, 5913 parents gave consent resulting in

67.7% of response rate per a school.

Methods

Trained assistants visited each school, administering surveys and taking anthropometric measurements.

Surveys similar in 2003 & 2011, some adjustments made in 2011.

Surveys included the Harvard Youth Adolescent Food Frequency Questionnaire known as YAQ, but adjusted it for the Canadian setting.

Methods

YAQ: Type of FFQ, used to assess diet quality, nutrient intake and caloric intake. •Why it was created

• Need for an instrument that could be administered to youth in large populations, be accurate, reproducible, and for repeated measures aimed towards the youth adolescent group.

• Original YAQ was based on the validated adult Nurses’ Health Study semi FFQ

• Decided to make it easier to complete

(Rockett. , Breitenbach, , & Frazier et al, (1997). Validation of a youth/adolescent food frequency questionnaire. Preventative Medicine, 26,)

Methods

Changes made to the YAQ– Original horizontal format to a vertical presentation, each food item

received an individual question and response– Snack section was placed last because it was easier for the

children/adolescents to fill out– Foods were grouped as a serving unit, for example instead of

inputting “1 hamburger patty, 1 bun” etc they answered 1 hamburger.

– The number of foods changed from 151 to 131 with some foods being added, deleted and combined with other food items on the questionnaire.

Input

What are some better procedures or implementations you believe could have been used in this study?

Results5215 Students 5508 Students

Participants

Table 3 (DRI and observed nutrient intake)Nutrient DRI Reference Mean SE 2003 2011Carbohydrate % AMDR 45-65 55.6±0.1 56.5±0.1g/d EAR 100 299.7±2.4 267.1±2.2Protein % AMDR 10.0-30 14.8±0.1 15.9±01g/kg/d EAR 0.76 1.94±0.02 1.84±0.02Fat % EAR 25-35 30.7±0.1 28.7±0.1g AMDR ND 73.4±0.06 60.2±0.5

Results, Fat, Carbohydrate and Protein

• Protein and Carbohydrate intake increased in 2011• Fat decreased from 2003 to 2011

Nutrient DRI Reference Mean SE

2003 2011

Vitamin C (mg) EAR 39 163.5±1.7 125.8±1.5

Folate EAR 250 363.8±2.8 335.2±2.5

Vitamin A (ug RAE/d)

Male EAR 445 918.7±12.6 898.5±10.9

Female EAR 420 901.1±12.7 881.8±10.6

Zinc (mg) EAR 7 10.2±0.1 9.5±0.1

Calcium (mg) EAR 1100 1181.9±9.7 1110±9.6

Sodium (mg) UL 2200 2615.1±20.6 2404.8±18.7

Results Vitamins and Minerals

• Vitamin C, Folate, Vitamin A and Calcium decreased but still met EAR• Sodium decreased but was still about the UL• Overall Calcium inadequacy increased in 2011

Discussion

Limitations– No comparison group– Some children were not measured for height and weight, ultimately

their information was not calculated into results. – Some responses in YAQ are subjective and maybe prone to error– FFQ may overestimate intakes, reliability of memory as opposed to

actually observing– Socioeconomic differences from 2003-2011– The sample group has changed.

Discussion

Strengths– Large amount of participants/response rates– Solid percentage of school participating– Provides real world evidence of population level

intervention– Used a validated FFQ

Discussion

This study helps us understand the importance of public policy Positive trends in diet quality No effect on overweight or obesity Improvements in energy intake

– Less energy intake from saturated fats No impact on fruit and vegetable consumption Limited consumption of SSB over time

– Did not differentiate from beverages consumed at home and school

Wrap Up

Thank you, any questions?