Identifying obesity and COVID-19 overlapping risk-factors: Protocol for a systematic review and meta-analysis.

This systematic review main goal is to identify the common risk factors of obesity and COVID-19 overall, and highlight the ones related to urban settings specifically, using a syndemic framework. COVID-19 highlighted the interaction between infectious diseases and non-communicable diseases. We hypothesise that obesity and COVID-19 share determinants, thus our main goal is to identify the overlapping risk factors and their magnitude of association with both health outcomes. Literature search was conducted in Medline and Embase, Cochrane Library and Epistemonikos, Web of Science and Scopus, ASSIA and SocINDEX and, Google Scholar, in June 2021. Covidence will be used to conduct the title and abstract, and full-text screening, considering the following inclusion criteria: (a) study addresses both health outcomes, (b) full-length articles, (c) study focuses on humans and (d) studies in English. The exclusion criteria will be: (a) study addresses one of the outcomes in combination with other pathologies, (b) not full-length article, (c) study focuses on animals, (d) study not written in English, (e) study focuses on treatment (pharmacological or other), testing (prognostic) or specific patients with other pathologies and (f) study focussed in clinical and/or physiological mechanisms associated with obesity and/or COVID-19. The included studies will be assessed for quality using the Effective Public Health Practice Project for quantitative studies and the tool described by Hawker for qualitative studies. Qualitative results will be assessed using thematic analysis methods to synthesise findings and presented in summary tables. Quantitative results - meta-analysis - will be analysed and presented using Q test and Funnel Plot.