Purpose: Latino- and African-Americans suffer disproportionately from obesity- and obesity-related cancers relativeto non-Latino Whites (NLWs). A large body of work has focused on addressing these disparities through individual-level obesity-related behaviors (diet, physical activity [PA]). Simultaneously, a growing body of work has highlightedthe role of contextual factors on disparities in obesity and obesity-related cancers, including neighborhood andcultural factors. Multilevel frameworks suggest that one way in which contextual factors impact obesity and obesity-related cancers among Latino- and African-Americans is through diet and PA. Yet, little work has evaluated empiricalevidence testing this multilevel hypothesis. Such data are warranted to understand if individual-level interventionsare sufficient or if direct intervention at the contextual-level is warranted to reduce disparities in obesity and obesity-related cancers.Objective: To conduct a systematic review and evaluate research that examined the influence of contextual levelfactors on obesity and breast and colorectal cancer via diet and physical activity.Method: Between June and July 2015, authors conducted a systematic review via electronic literature searchesusing PubMed and Web of Knowledge databases. Studies were included if they reported a measure of a) cultural and/or neighborhood factors, b) obesity and obesity-related cancers, c) physical activity and diet, targeted African-and Latino-American populations, and conducted a test of mediation effects of diet and/or PA.Results: Of the 229 titles identified, 177 abstracts and 7 full text articles were reviewed. Of the 7 articles reviewed, 5specifically tested diet and PA as pathways in the relationship between contextual factors and obesity. All studiesfocused on PA-related behaviors as mechanisms, and one included diet. Studies varied in terms of measurement ofdiet and PA. Among the studies that investigated neighborhood-level factors, only one study found evidence of PAas a mediator. This study found that infrastructure for walking was indirectly related to obesity via accelerometer-measured PA. Two studies examining cultural factors linked acculturation and obesity via PA-specifically ifmeasured as sedentary behavior as well as leisure-time, transportation-related, and work-related PA.Conclusion: The evidence remains limited in terms of whether individual-level behaviors underlie the effects ofcontextual factors on obesity- and obesity-related cancers among Latino- and African-Americans. Indeed, little to noresearch examines these relationships in terms of two more commonly studied obesity-related cancers, and littlework has assessed diet as the mechanism by which contextual factors influence obesity. To understand whichinterventions are optimal for addressing these multifaceted disparities, further research is needed to clarify if andhow context influence health behaviors .