LAUSR

Short sleep increases the risk for obesity in adolescents. One potential mechanism relates to when eating occurs in the day. This study investigated the impact of shortened sleep on eating occasion timing in adolescents. Ninety‐three healthy 14‐ to 17‐year‐olds (62% female) completed a within‐subject experimental sleep manipulation, engaging in 5‐night spans of Short Sleep (6.5‐hr sleep opportunity) or Healthy Sleep (9.5‐hr sleep opportunity), with order randomized. During each condition, adolescents completed three 24‐hr diet recall interviews. Repeated‐measure t‐tests assessed the sleep manipulation effect on each adolescent's number of meals, first and last eating occasion (relative to the clock and time since sleep onset/offset), feeding window (timespan from first to last eating), and the midpoint of feeding. The timing of the first eating occasion was similar across conditions, relative to the clock (Short = 08:51, Healthy = 08:52) and to time since waking (Short = 2.0 hr, Healthy = 2.2 hr). The timing of the last eating occasion was later relative to the clock (Short = 20:34, Healthy = 19:39; p < 0.001), resulting in a longer feeding window (Short = 11.7 hr, Healthy = 10.8 hr, p < 0.001) and a later midpoint in the feeding window (Short = 14:41, Healthy = 14:18, p = 0.002). The gap between last eating occasion and sleep onset was larger in Short (4.2 hr) than Healthy Sleep (2.9 hr; p < 0.001), though the last eating occasion was much earlier than when they fell asleep during either condition. Shortened sleep resulted in adolescents eating later and lengthening the daily feeding window. These findings may help explain the link between shortened sleep and increased obesity risk in adolescents.