In recent years, many original studies have shown that skipping breakfast has been associated with overweight and obesity; however, the results of different studies are inconsistent. Therefore, we conducted a systematic review and meta-analysis of observational studies to synthesize the associations between skipping breakfast and the risk of overweight/ obesity.

We did a systematic search using Pubmed, and Ovid searched up to August 2019. Observational studies (cohort studies and cross-sectional studies) reporting adjusted Odds Ratio or Risk Ratio estimates for the association between breakfast skipping and overweight/obesity (including abdominal obesity). Summary odds ratio (or Risk Ratio) and 95% confidence intervals calculated with a random-effects model.

45 observational studies (36 cross-sectional studies and 9 cohort studies) were included in this meta-analysis. In cross-sectional studies, The ORs of low frequency breakfast intake per week versus high frequency were 1.48 (95% CI 1.40–1.57; I²=54.0%; P=0.002) for overweight/obesity, 1.31 (95% CI 1.17–1.47; I²=43.0%; P=0.15) for abdominal obesity. In cohort studies, The RR of low-frequency breakfast intake per week versus high frequency was 1.44 (95% CI 1.25–1.66; I²=61%; P=0.009) for overweight/obesity.

This meta-analysis confirmed that skipping breakfast is associated with overweight/obesity, and skipping breakfast increases the risk of overweight/obesity. The results of cohort studies and cross-sectional studies are consistent. There is no significant difference in these results among different ages, gender, regions, and economic conditions.