Is self-reported short sleep duration associated with obesity? A systematic review and meta-analysis of cohort studies

Abstract Context A possible association between self-reported short sleep duration and risk of obesity has been studied. Objective To analyze the association between sleep duration and obesity. Methods The LILACS, Medline, Central, Embase, and OpenGrey databases were searched from inception until July 2020. Two authors screened the studies independently according to the PECO strategy, as follows: participants: > 18 years old; exposure: short sleep duration; control: regular sleep; outcome: obesity). Only cohort studies were included. A total of 3286 studies were retrieved with the search strategy, but only 36 were included. Disagreements were resolved by a third author. The quality of studies was assessed with Newcastle-Ottawa Quality Assessment Form for Cohort Studies. The certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation. Results Thirty-six studies were included, and 22 contributed quantitative data. Most of the studies (n = 27) assessed sleep by self-report. The meta-analysis showed a significant association between self-reported short sleep and development of obesity, and the chances of developing obesity increased when self-reported sleep duration decreased. Conclusions Self-reported short sleep was significantly associated with a higher incidence of obesity, with moderate quality of evidence. Systematic Review Registration PROSPERO registration no. CRD42019130143.