© 2016 by the Oncology Nursing Society. Obesity may contribute to development and recurrence of cancer, as well as cancerrelated and all-cause mortality. This risk factor is also among the most preventable causes of cancer. This article describes current evidence-based guidelines for weight management and physical activity for cancer survivors. The authors also discuss practical interventions to help survivors undertake behavioral changes to manage their weight. At a Glance • Obesity is a risk factor for cancer development and recurrence. • Cancer survivors should be encouraged to practice portion control and substitute foods, such as vegetables, fruits, and whole grains, for foods high in calories but of little nutritional value, such as desserts, soft drinks, potato chips, and fried foods. • Cancer survivors should include a minimum of 150 minutes per week of aerobic exercise and two days per week of strength training.