Diet and Exercise Program to Promote Weight Loss and Improve Health in Men With Low- or Low-Intermediate-Risk Prostate Cancer

This randomized phase III trial studies a diet and exercise program based on the Diabetes Prevention Program to promote weight loss and improve health in men with low-risk or low-intermediate-risk prostate cancer on active surveillance. A lifestyle intervention that promotes weight loss may influence prostate health. A combined diet and exercise program that is based on the Diabetes Prevention Program may affect markers (or \"biomarkers\") of prostate cancer progression. Gathering this information may help doctors understand how obesity affects prostate cancer progression and may help lead to a program that can reduce the risk of prostate cancer progression.