Dr. Patrice L. Capers, a MERIT post-doctoral scholar in the office of energetics at the University of Alabama at Birmingham School of Public Health, notes that “recent epidemiological and ecological trends in humans indicate a possible causal relationship between sleep duration and energy balance,” so — in collaboration with Dr. Aaron Davis Fobian, assistant professor in UAB department of psychiatry; Dr. Kathryn Kaiser, instructor in the office of energetics; Mr. Rohit Borah, MPH student and research analyst in the office of energetics and Nutrition Obesity Research Center (NORC); and Dr. David B. Allison, distinguished professor and director of the office of energetics and NORC — she sought experimental evidence of a link between sleep duration and body composition, food intake, or biomarkers related to food intake.
Conducting a systematic literature review, the team searched six electronic databases for published randomized controlled trials (RCTs) that manipulated sleep duration and measured body weight or other body composition metrics, food intake, and/or biomarkers related to eating. They identified 18 unique studies that reported at least one outcome meeting all criteria: eight reporting an outcome of body weight (four: increased sleep; four: reduced sleep); four reporting on the effect of short sleep on food intake; four reporting on the effects of sleep restriction on total energy expenditure and three reporting on respiratory quotient; and four studies examining effects on leptin and/or ghrelin. Of these 18 included studies, 16 studies contained objective measures of body composition and/or energy balance that could be included in the meta-analysis.
“We found that there are few RCTs that have studied the question of the effect of sleep duration on body weight/composition and eating over long periods. The available experimental literature suggests that acute sleep restriction increases food intake and total energy expenditure with inconsistent effects on integrated energy balance as operationalized by weight change. The studies that increased sleep duration were found to have statistically significant effects on weight loss, although results were inconsistent between the included studies and clinical effectiveness remains to be demonstrated,” says Dr. Capers.
Based on this study’s findings, the current literature on experimental studies does not provide a strong basis to support or refute a causal relationship between sleep duration and weight change in humans. Therefore, the researchers recommend that “future controlled trials that examine the impact of increased sleep on body weight/energy balance factors are warranted.”
“A Systemic Review and Meta-Analysis of Randomized Controlled Trials of the Impact of Sleep Duration on Adiposity and Components of Energy Balance” was published online in June in the journal Obesity Reviews.
Journal article: http://www.ncbi.nlm.nih.gov/pubmed/26098388?dopt=Abstract