School nutrition policy adherence and weight status in elementary school children in Prince Edward Island

摘要

The majority of Canadian provinces have adopted school nutritionpolicies (SNP) in an effort to improve children‟s eating habits and reducechildhood overweight and obesity. While a number of provinces haveimplemented SNPs, there has been little in terms of evaluation across thecountry. All elementary schools in Prince Edward Island (PEI) adopted a SNP in2005-2006. The purpose of this study was to describe the changes in SNPadherence over time, as well as assess the impact that SNP adherence has onchildren‟s overweight and obesity rates. A self-administered survey wasdistributed to all elementary school principals in 2007 and 2010. The PrincipalSchool Food Survey (Appendix A) consisted of both a subjective and moreobjective component to assess the level of implementation of all SNP elements.The perceived adherence score was calculated using the responses from 15subjective questions. Food list adherence, the more objective measure ofadherence, was assessed by comparing the reported food and beverage items soldat lunch, in vending machines and canteens to policy guidelines. The relationshipbetween overweight and obesity rates and both measures of adherence wasassessed for 2010 only. It was predicted that schools with a higher level ofadherence would have lower rates of overweight and obesity. Non-parametrictests (Wilcoxon rank sum, chi-square and Spearman‟s rho) were used to assesschanges in perceived adherence, food list adherence and the agreement betweenfood list and perceived adherence respectively. Logistic regression was used toassess the impact that the level of policy adherence had on overweight andobesity rates.Results indicated that perceived adherence was higher in 2010 than 2007(Mann-Whitney U= 519.5, p =0.007). Food list adherence for lunch programitems and canteen items decreased significantly from 2007 to 2010 (x2= 12.576,df=3, p=0.006) while vending machines item adherence increased slightly duringthe same time period (x2=13.689, df=1, p=0.008). There was no significantagreement between overall perceived adherence scores and food list adherence;however, a few policy elements (pricing foods to encourage healthyconsumption, promote healthy advertising, serve foods from „most often‟ or„sometimes‟ list) did reveal a positive relationship with 2007 food list adherence.There was some support for the hypothesis for the overweight model, in thatcloser policy adherence (% allowed foods) was associated with lower overweightrates in elementary school children. The study also found that schools withhigher perceived adherence scores had increased rates of overweight amonggrade 5 and 6 children. The level of adherence was not, however, a significantpredictor of obesity rates. These findings are consistent with previous researchdemonstrating the impact of SNP adherence on overweight rates but not obesity.This study also found that physical activity, breakfast consumption, low-nutrientdensity food (LNDF) consumption, student sex and parental education weresignificant predictors of both overweight and obesity; in addition to these factors,parental income and television frequency were also predictors of obesity. Therelationships between the co-variates and overweight and obesity were in the3expected direction. While the adoption of a SNP can be a positive first step tochange the school food environment, promote healthy eating habits and reduceoverweight among children, more comprehensive evaluation methods (ie.objectively assessing adherence to all policy elements as opposed to justavailable food and beverage items) are needed to identify potential barriers toimplementation and accurately assess the impact of such policy interventions.