Lifestyle behaviors, including diet modification and physical activity, are needed for weight loss and successful long-term weight loss maintenance. This review highlights recent studies that have suggested the importance of these behavior changes and new strategies that appear effective for modifying diet and exercise. The benefits of food provision and meal replacement strategies are reviewed. Home-based exercise, methods for accumulating exercise through multiple short bouts, and decreasing sedentary behavior have all been studied recently and appear to be promising new approaches to the promotion of physical activity. Finally, the review describes recent research on several new areas related to lifestyle change, including ways to extend therapists’ contact with patients through enhanced social support and Internet interventions, strategies for prevention of weight gain, and the role of physicians in weight loss counseling.