Comparison of Fruit and Vegetable Intake from School and Packed Lunches: Intra‐Individual Variation Across the School Week
Authors: Taylor Jennifer C , Sutter Carolyn , Ontai Lenna , Nishina Adrienne , Zidenberg‐Cherr Sheri 
Published: November 2023

Growing evidence suggests the nutritional quality of packed lunches falls short of school meals. Prior studies have objectively compared school and packed lunches in terms of fruit and vegetable selection, but less is known about what is actually consumed from these lunches. In addition, studies have typically observed students over a single lunch, but multiple lunch observations may be needed to capture a reliable representation of diet if students' behaviors vary each day. The objective of this study was to compare fruit and vegetable selection and consumption among students choosing school or packed lunches over five consecutive days. Participants were fourth‐, fifth‐, and sixth‐grade students (N = 315) recruited from three elementary schools. Each student was observed over a period of five consecutive days during lunch, resulting in a final sample of 1,164 observations. Trained analysts estimated food selection and consumption from digital images and written records collected before and after lunchtime. Poisson regression models examined the odds of selecting and consuming fruit and vegetables at lunch each day (event occurring on 0–5 days) across the school week depending on lunch type. Most students (81%) chose the same type of lunch daily, consistently choosing either a packed lunch (n = 140) or a school lunch (n = 117). Among these students, 59% always selected and 37% always consumed fruit, respectively, while 35% selected and 46% consumed fruit only on some days of the week. Sixteen percent of students always selected and 11% always consumed vegetables, respectively, while more than 60% selected and consumed vegetables only on some days of the week, exhibiting day‐to‐day variability in these behaviors. This pattern, where a dietary behavior varied across the week (e.g., selected vegetables some days of the week, rather than always or never selecting vegetables), was more common among students choosing school lunches than packed lunches for both vegetable selection (χ2[1, 256] = 18.86, P < .001) and consumption (χ2[1, 256] = 23.87, P < .001). Students choosing school lunches were more likely than those choosing packed lunches to select fruit (odds ratio [OR], 1.28; 95% CI, 1.12–1.46), consume fruit (OR, 1.36; 95% CI, 1.11–1.51), and select vegetables (OR, 1.21; 95% CI, 1.02–1.43) on a greater number of days, although they did not differ for vegetable consumption. Aligning with prior studies, this study found that students choosing packed lunches were less likely to include fruit and vegetables at lunchtime than those choosing school meals. Given that a large proportion of students selected and consumed these foods only on some days of the week, further research is needed to examine intra‐individual variability in lunchtime dietary behaviors among students choosing school and packed lunches.Support or Funding InformationFunding was provided by the Henry A. Jastro Scholarship Fund and an Academic Federation Innovative Developmental Award.