In light of recent school-policy movements that encourage recess be moved before lunch, the present study seeks to examine the relationship between food consumption and immediate, subsequent physical activity (PA) and, more specifically, if a risk would be posed to the amount of children's PA if food is not consumed directly before activity. A cross-section study was performed measuring (a) lunch composition (in terms of food groups defined by the USDA's food plate), (b) lunch consumption, and (c) moderate-to-vigorous physical activity (MVPA) during the following recess period, in consenting third through sixth grade students. The relationship between food consumption and percentage of recess time spent in MVPA was determined to be weak. However, the study identified low average provision and consumption rates across all food groups and evaluated this through the lease of current school lunch policy/formatting.
Methods: Study participants (n=1469) were elementary and middle school students who ate school lunch on the day of data collection. Photographs and weights (to nearest 2 g) were taken of fruits and vegetables on students’ trays before and after lunch. Trained research assistants viewed photographs and sorted trays into variable categories: color of main tray, presence/absence of secondary fruit/vegetable container, and color of secondary fruit/vegetable container. Fruit and vegetable selection, consumption, and waste were calculated using tray weights. Negative binomial regression models adjusted for gender, grade level, race/ethnicity, free/reduced price lunch status, and within-school similarities were used to examine relationships between tray color and fruit and vegetable selection, consumption, and waste.
Results: Findings indicated that students with a light tray selected (IRR= 0.44), consumed (IRR=0.73) and wasted (IRR=0.81) less fruit and vegetables. Students without a secondary fruit/vegetable container selected (IRR=0.66) and consumed (IRR=0.49) less fruit and vegetables compared to those with a secondary container. Light or clear secondary fruit and vegetable containers were related to increased selection (IRR=2.06 light, 2.30 clear) and consumption (IRR=1.95 light, 2.78 clear) compared to dark secondary containers, while light secondary containers were related to decreased waste (IRR= 0.57).
Conclusion: Tray color may influence fruit and vegetable selection, consumption, and waste among students eating school lunch. Further research is needed to determine if there is a cause and effect relationship. If so, adjusting container colors may be a practical intervention for schools hoping to increase fruit and vegetable intake among students.