Retail food outlets and metabolic syndrome: a systematic review of longitudinal studies

Context The community food environment covers the type, quantity, density, location, and access to retail food outlets, and its influence on eating behavior, obesity, and metabolic syndrome has been investigated. Objective To evaluate the evidence on longitudinal associations between objectively measured retail food outlets and metabolic syndrome components in children, adolescents, and adults. Data extraction This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study quality and risk of bias were assessed with the Newcastle-Ottawa Scale. Data sources The Scopus, Embase, Web of Science, Scielo, PubMed, MEDLINE, and Lilacs databases were searched without any restriction on publication dates. Data analysis Of the 18 longitudinal studies included, significant associations were reported in 9 between retail food outlets and metabolic syndrome components in adults (6 positive associations, 2 negative, and 1 both positive and negative), and in 3 studies of children and adolescents (2 negative associations and 1 both positive and negative). Six studies with adults found no association. Conclusion Limited evidence was found for longitudinal associations between retail food outlets and metabolic syndrome components. In future studies, researchers should consider the use of standardized retail food outlet measurements and accurate analysis to better understand the influence of the community food environment on metabolic syndrome. Systematic Review Registration PROSPERO registration no: CRD42020177137.