Relationship Between Sleep Duration and Overweight/Obesity: A Comprehensive Overview of Meta‐Analyses

Overweight and obesity are increasing globally and have an important impact on individuals' health and healthcare costs. Several factors contribute to this growth, and changes in normal sleep duration (SD) have been recognised. This relationship has given rise to numerous systematic reviews with meta-analyses (SRMAs) over the last years. Thus, synthesising these studies could help researchers and clinicians offering the highest level of evidence synthesis. Therefore, we aimed to provide a comprehensive overview of SRMAs that explored the relationship between SD and overweight/obesity. Searches were conducted in PubMed, Web of Science, Embase and Scopus. The quality of the reviews was evaluated using the Risk Of Bias In Systematic reviews (ROBIS) tool. The inverse variance heterogeneity model (IVhet) was adopted to assess the pooled relative risks (RR) and 95% confidence intervals (CIs) of SRMAs. After the selection process, 18 SRMAs were included in the synthesis. Short SD increased the risk of being overweight/obese in younger children (RR = 1.39; 95% CI: 1.27-153), older children (RR = 2.21; 95% CI: 1.59-3.07), adolescents (RR = 1.36; 95% CI: 1.22-1.51) and adults (RR = 1.30; 95% CI: 1.17-1.44). Long SD increases the risk in adults (RR = 1.05; 95% CI: 1.02-1.08), but has a protective effect in children (RR = 0.86; 95% CI: 0.78-0.95). These findings reinforce the role of SD as a significant and modifiable risk factor for overweight and obesity.