{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T10:33:42Z","timestamp":1785407622710,"version":"3.56.0"},"reference-count":23,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:00:00Z","timestamp":1784678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Stanford University School of Medicine Propel Postdoctoral Scholars Program","award":["U24DK132733"],"award-info":[{"award-number":["U24DK132733"]}]},{"award":["U24DK132733"],"award-info":[{"award-number":["U24DK132733"]}],"id":[{"id":"https:\/\/ror.org\/00f54p054","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Clocks &amp; Sleep"],"abstract":"<jats:p>Sleep characteristics have been associated with body mass index (BMI) among adolescents, but population-representative evidence on sleep timing and variation across demographic subgroups remains limited. We conducted a cross-sectional analysis of 2017\u20132018 California Health Interview Survey data from 880 adolescents aged 12\u201317 years. Weeknight sleep duration was obtained from the CHIS-derived sleep-duration variable, based on reported school-night bedtimes and school-day wake times. Sleep-timing measures included bedtime, wake time, and the derived sleep midpoint. Pooled survey-weighted linear and logistic regression models used 160 jackknife replicate weights and adjusted for age, sex, race\/ethnicity, household poverty category, and survey year; sensitivity models additionally adjusted for dietary and behavioral factors. Sleep duration was not associated with BMI overall (p = 0.161) or with the odds of having overweight or obesity (p = 0.36). The association between sleep duration and BMI varied by age group (p for interaction = 0.042). Each additional hour of sleep was associated with a lower BMI among adolescents aged 14\u201317 years (\u03b2 = \u22120.895 kg\/m2; 95% CI: \u22121.464 to \u22120.326; p = 0.002), but not among those aged 12\u201313 years. However, there was no evidence of an interaction when age was modeled continuously (p for interaction = 0.36). Bedtime, wake time, and sleep midpoint were not independently associated with BMI. Exploratory evidence that the association between sleep duration and overweight or obesity varied by race\/ethnicity was attenuated after adjustment for dietary and behavioral factors (p for interaction changed from 0.04 to 0.05). In this cross-sectional study, neither sleep duration nor sleep timing was associated with BMI in the overall sample, and sleep duration was not associated with BMI-defined weight status. Subgroup findings were not consistent across model specifications and should be examined in longitudinal studies using objective and repeated measures of sleep.<\/jats:p>","DOI":"10.3390\/clockssleep8030045","type":"journal-article","created":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T09:20:39Z","timestamp":1784712039000},"page":"45","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Sleep Duration and Body Mass Index Among Adolescents: Variation by Age and Race\/Ethnicity"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8187-3492","authenticated-orcid":false,"given":"Astrid N.","family":"Zamora","sequence":"first","affiliation":[{"name":"Department of Epidemiology and Population Health, School of Medicine, Stanford University, Stanford, CA 94304, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8328-0199","authenticated-orcid":false,"given":"Zachary P.","family":"Gersten","sequence":"additional","affiliation":[{"name":"Department of Nutrition, University of California at Davis, Davis, CA 95616, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erica C.","family":"Jansen","sequence":"additional","affiliation":[{"name":"Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA"},{"name":"Department of Neurology, Division of Sleep Medicine, Michigan Medicine, Ann Arbor, MI 48109, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1970","DOI":"10.1111\/jan.15513","article-title":"Associations between sleep and overweight\/obesity in adolescents vary by race\/ethnicity and socioeconomic status","volume":"79","author":"Ji","year":"2023","journal-title":"J. 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