Could healthy eating initiatives be contributing to obesity? An analysis of primary school children's packed lunches before and after a healthy eating initiative

Abstract

BackgroundIncreasing rates of obesity have become a major concern for the western world, and one way in which the UK Government has attempted to tackle the issue is to promote healthy eating. For example, the five-a-day campaign encourages increased consumption of fruit and vegetables. The assumption that this change will promote healthy weight is common, although evidence suggests that addition of fruit and vegetables to the diet will not tackle obesity unless fruit and vegetables are replacing high fat and sugary foods. Although it is generally uncontroversial that a diet containing five fruits or vegetables a day has health benefits, the target has become a panacea for many healthy eating interventions. However, increasing of fruit and vegetable consumption could be detrimental if it also increases overall calorific intake. The objective of this research was to investigate whether increased fruit and vegetable consumption resulting from a healthy eating intervention affected calorific intake. Using a healthy eating initiative for children of primary school age, we aimed was to measure whether children who increased their lunchbox fruit consumption after the intervention, showed any change in their calorific intake. MethodsAn observational study of children's lunchboxes measured food consumed before a healthy eating intervention and at 3-month follow-up. Three intervention schools (n=63) were matched with three control schools (n=64). Portions of fruit and vegetables and total calories consumed were calculated with a comprehensive online food database (Weight Loss Resources). A subgroup of children from the intervention schools, who showed increased fruit and vegetable consumption and for whom it could be judged that the intervention had been successful, were analysed to investigate the effect on their calorific intake. Comparisons were made with the remaining intervention schoolchildren and the control group. Additionally, the general relation between changes in fruit and vegetable consumption and calorific intake was explored in data from all participants. FindingsMean fruit and vegetable consumption increased slightly in the intervention schools and decreased slightly in the control schools between baseline and follow-up. Mean calorific consumption showed a slight increase in both the intervention and control groups, but mixed measure ANOVAs and paired t tests showed none of these differences to be significant. However, the group with increased fruit and vegetables consumption (n=35) showed a significant increase in calorific consumption between baseline (mean 400 kcals, SD 100) and follow-up (431 kcal, SD 103; p=0·031). No significant differences were recorded for either children without increased fruit and vegetable consumption or the control group. A positive correlation was identified between increased fruit and vegetable consumption and calorific intake for all children (r=0·203, n=127, p=0·022). InterpretationThe significant increase in calories for the group with increased fruit and vegetable consumption after the intervention suggests that this increased consumption had not displaced other foods. The positive correlation also suggests that fruit and vegetable consumption generally is not displacing higher calorific foods. This finding does not support assumptions that have been made about the relation between fruit and vegetable consumption and healthy weight. By contrast, interventions that aim to increase fruit and vegetable consumption could be adding to overall calorific consumption. The implications of encouraging the population to eat more fruit and vegetables need to be established. FundingThis research was self-funded by CH as the independent research undertaken for her MSc in Psychological Research Methods with the Open University.