Differences in children’s meal timing between school and summer: three-year findings from the what’s UP (Undermining Prevention) with summer observational cohort study

Later meal timing, increased variability in timing, and meal skipping are associated with negative health outcomes among children. Few studies examine whether these behaviors are different between the school year and summer. This study analyzed changes in meal timing (i.e., absolute timing, variability in timing, and meal skipping) from the school year to summer in elementary-aged children, and whether changes differed by child age, child sex, and/or household income. Parents ( n = 1,004) of 1,004 children (ages 5–14 years, 50% girls) completed a daily diary for 14 days during school and summer from 2021 to 2023. Parents reported if their child consumed breakfast, lunch, and dinner, and if so, at what time(s). Multilevel models examined changes in absolute timing (clock time) and variability in timing (individual standard deviation, SD) from school to summer. Logistic multilevel models were used to examine odds of skipping meals. All models controlled for child age, child sex, and household income, which were further examined as moderators. During summer, compared to the school year, children consumed all meals later (breakfast: +89.5 min, 95%CI: 88.3–90.7; lunch: +53.8 min, 52.8–54.9; dinner: +11.6 min, 10.5–12.8), had greater breakfast (+ 9.2 min SD, 7.0-11.3) and lunch (+ 9.8 min SD, 8.2–11.4) timing variability, and had higher odds of skipping meals (breakfast: OR:2.0, 95%CI: 1.8–2.2; lunch: 4.6, 3.7–5.7; dinner: 1.8, 1.4–2.5). Income moderated absolute timing changes (breakfast: high-income 8.3 min earlier than low-income; lunch: high-income 20.6 min earlier than low-income, middle-income 12.8 min earlier than low-income). Age moderated absolute timing of breakfast (5.8 min earlier/one-year age increase) and breakfast and lunch timing variability (breakfast:+1.7 min/one-year increase; lunch:+1.6 min/one-year increase). Breakfast skipping was moderated by age (OR interaction: 0.86, 95%CI: 0.81–0.91) and child sex (OR interaction: 0.75, 0.62–0.92). Lunch skipping was moderated by income (OR interaction: High vs. Low(ref): 1.78, 1.01–3.14). Children consumed all meals later, had more breakfast and lunch timing variability, and higher odds of skipping meals during summer compared to the school year. Child age, child sex, and household income moderated some of these associations. Research is needed to further understand how different summer environments influence meal timing to support the development of healthful dietary habits and chronic disease prevention.