Environmental factors may operate differently when relations are measured across different geographical locations, a phenomenon known as spatial non-stationarity (SNS), thus leading to biased conclusions and often ignored in past studies. This study investigates the SNS effect of unhealthy food environments and green spaces on the diabetes prevalence rate (DPR) between age groups in Toronto's neighborhoods. Geographically weighted regression models are utilized to explore the impacts of SNS. The results from this study reveal that environmental variables dissimilarly affect diabetes prevalence rates among age groups and neighborhoods in Toronto after controlling for socioeconomic factors. For example, green space density yields positive associations with DPR for elder generations but negative relationships for younger age groups around Toronto East. The observed associations will provide recommendations to support authorities in designing targeted intervention programs to control DPR.