Investigating the mediating role of physical activity within the association between food insecurity and BMI

Food insecurity is linked with obesity and while the mechanisms behind this association are complex, lower levels of leisure-time physical activity in those with food insecurity may contribute to this. Individual-level factors (such as concerns of performing physical activity) may partly determine levels of physical activity within individuals with food insecurity, as such individuals may seek to minimise their levels of physical activity in order to preserve energy. Using the Food Insecurity Physical Activity Concerns Scale (FIPACS) (used to measure concerns of performing leisure-time physical activity, focusing on factors specific to food insecurity), the current study investigated whether the association between household food insecurity and body mass index (BMI) is explained by a mediation pathway of FIPACS scores and leisure-time physical activity. We also investigated whether the association between food insecurity and FIPACS scores is moderated by nutrition knowledge. Participants (N = 329, food insecure = 55) completed an online survey consisting of the FIPACS, the International Physical Activity Questionnaire long-form (IPAQ), the Diet, Disease, and Weight management sub-section of the General Nutrition Knowledge Questionnaire, a measure of diet quality, and self-reported BMI. Findings revealed that FIPACS scores and leisure-time physical activity did not mediate the association between food insecurity and BMI (b < 0.01, SE = 0.01). Additionally, nutrition knowledge did not moderate the association between food insecurity and FIPACS scores (b = -0.09, SE = 0.08). Findings suggest that concerns of performing physical activity in the context of food insecurity are unrelated to leisure-time physical activity, and that these two factors do not explain the association between food insecurity and BMI. Future research should investigate other factors in the link between food insecurity, physical activity, and BMI.