ObjectiveBeyond sleep duration, other facets of sleep such as variability and timing may be associated with obesity risk in youth. However, data are limited. Using a longitudinal design, this study tested whether multiple facets of sleep were associated with fat mass gain over 1 year.MethodsA convenience sample of non‐treatment‐seeking youth (age 8‐17 years) wore actigraphy monitors for 14 days. Average weekly sleep duration, within‐person sleep duration variability, weekend catch‐up sleep, bedtime and wake time shift, social jet lag, bedtime, wake time, and sleep midpoint were calculated. The association of each facet of baseline sleep with 1‐year fat mass, adjusting for baseline fat mass and height, was examined.ResultsA total of 137 youths (54.0% female; mean [SD], age 12.5 [2.6] years; 28.4% non‐Hispanic Black or African American; baseline fat mass = 15.3 [8.9] kg; 1‐year fat mass = 17.0 [10.0] kg; 28.5% with baseline overweight or obesity) were studied. Wake time (p = 0.03) and sleep midpoint (p = 0.02) were inversely associated with 1‐year fat mass, such that earlier wake time and midpoint were associated with higher 1‐year fat mass. No other facet of sleep was significantly associated with 1‐year fat mass (p > 0.09).ConclusionsUsing objective measures, youth with earlier wake times and sleep midpoints had greater gains in fat mass. Additional research is needed to determine whether sleep timing may be a modifiable target to prevent pediatric obesity.

Summary Background Inconsistent sleep patterns may promote excess weight gain by increasing food cravings and loss‐of‐control (LOC)‐eating; however, these relationships have not been elucidated in youth. Objective We tested whether sleep duration and timing were associated with food cravings and LOC‐eating. Method For 14 days, youths wore actigraphy monitors to assess sleep and reported severity of food cravings and LOC‐eating using ecological momentary assessment. Generalized linear mixed models tested the associations between weekly and nightly shifts in facets of sleep (i.e., duration, onset, midpoint, and waketime) and next‐day food cravings and LOC‐eating. Models were re‐run adjusting for relevant covariates (e.g., age, sex, adiposity). Results Among 48 youths (12.88 ± 2.69 years, 68.8% female, 33.3% with overweight/obesity), neither weekly nor nightly facets of sleep were significantly associated with food cravings (ps = 0.08–0.93). Youths with shorter weekly sleep duration (est. ß = −0.31, p = 0.004), earlier weekly midpoints (est. ß = −0.47, p = 0.010) and later weekly waketimes (est. ß = 0.49, p = 0.010) reported greater LOC‐eating severity; findings persisted in adjusted models. Conclusions In youth, weekly, but not nightly, shifts in multiple facets of sleep were associated with LOC‐eating severity; associations were not significant for food cravings. Sleep should be assessed as a potentially modifiable target in paediatric LOC‐eating and obesity prevention programs.

Objective: Among youth with overweight, food cravings (FC) are associated with lossof-control (LOC)-eating, but the impact of sex-associated biological characteristics on this relationship is unknown. We examined whether sex and gonadal hormone concentrations moderated the relationships between FC and LOC-eating severity among healthy boys and girls across the weight strata in natural and laboratory environments.Method: Using ecological momentary assessment (EMA), FC, and LOC-eating severity were reported 3-5 times a day for 2 weeks. In the laboratory, participants reported FC, consumed lunch from a buffet test meal designed to simulate LOC-eating, and rated LOC-eating severity during the meal.Results: Eighty-seven youth (13.0 ± 2.7 years, 58.6% female, 32.2% with overweight/obesity) participated. EMA measured general and momentary FC were positively associated with LOC-eating severity (ps < .01), with no differences by sex (ps = .21-.93). Estradiol and progesterone significantly moderated the relationships between FC and LOC-eating such that general FC and LOC-eating severity were only positively associated among girls with greater (vs. lower) estradiol (p = .01), and momentary FC and LOC-eating severity were only positively associated among girls with greater (vs. lower) progesterone (p = .01). Boys' testosterone did not significantly moderate the associations between FC and LOC-eating severity (ps = .36-.97). At the test meal, pre-meal FC were positively related to LOC-eating severity (p < .01), without sex or hormonal moderation (ps = .20-.64).Discussion: FC were related to LOC-eating severity in boys and girls. In the natural environment, gonadal hormones moderated this relationship in girls, but not boys.The mechanisms through which gonadal hormones might affect the relationship between FC and LOC-eating warrant investigation.