Protein and Energy Intakes Are Skewed toward the Evening among Children and Adolescents in the United States: NHANES 2013-2014.

Background: Emerging evidence suggests that the timing, amount at individual eating occasions, and distribution of protein and energy intakes throughout the day may affect health. Objective: We examined the timing, amounts, and distribution of protein and energy intakes throughout the day among participants aged 4-18 y in the United States in the context of chronobiology and nutrition. Methods: This cross-sectional analysis included 2532 participants aged 4-18 y who completed the first interviewer-administered 24-h dietary recall in NHANES 2013-2014. Descriptive statistics for intakes across the day were provided as percentiles, means ± SEMs, and percentages of nonconsumers. Statistical differences between intakes across the day were tested with the use of individual-level fixed-effects regression models. Cumulative distribution functions were used to examine the timing of the first and last caloric eating occasion. Results: Mean ± SEM protein (grams) and energy (percentage of the day) intakes were significantly higher ( P < 0.05) in the evening than in the morning among all age groups. The percentage of participants aged 4-8, 9-13, and 14-18 y who had their first eating occasion at or after 1100 was 4%, 14%, and 20%, respectively, and the percentage who had their last eating occasion at or after 2100 was 8%, 19%, and 34%, respectively. Conclusions: Protein and energy intakes among participants aged 4-18 y in this study were largest in the evening and midday and smallest in the morning and afternoon. Clinical trials are needed to assess any potential impact such dietary behaviors may have on health outcomes related to metabolic dysfunction in children and adolescents.