The association of physical activity with obesity and NCD outcomes: insights from Kenyan panel data

Physical activity (PA) levels in Sub-Saharan Africa are declining due to technological advancements that reduce physical exertion. The aim of this study was to evaluate the longitudinal associations between occupational, leisure, and transport-related PA, as well as sedentary time, on weight and the likelihood of developing a non-communicable disease (NCDs) in Kenya. The study used panel data collected in 2015 and 2022 from 166 participants, selected through a three-stage cluster sampling design. A fixed effects model accounted for unobserved, time-invariant heterogeneity, with results further validated using entropy balancing. Findings indicate declining PA levels, rising sedentary time, and increases in both body mass index (BMI) and NCD incidence. Each additional MET-hour per week of leisure PA is associated with a 0.16% lower BMI, while transport and vigorous occupational PA are associated with 0.052% and 0.025% lower BMI, respectively. A one-unit increase in MET-hours per week of leisure, vigorous occupational, and moderate occupational PA is associated with a 0.53%, 0.15%, and 0.11% lower probability of developing an NCD, respectively. In contrast, sedentary time is positively associated with a 0.18% higher probability of developing an NCD. This study highlights the need for policies promoting PA across all domains, and investments in infrastructure that support active transport and recreational activity to combat obesity and NCDs in Kenya.