The current obesity epidemic can be attributed, in large part, to a "modern" environment that discourages physical activity and encourages the consumption of supersized portions of energy-dense foods. Traditional approaches that have emphasized education and individual responsibility alone are unlikely to be effective. Most people know what they must do to lose weight permanently or prevent weight gain, but they are unable to implement the needed lifestyle changes. Thus, efforts toward the prevention of obesity must both aid individual persons in maintaining cognitive controls over their weight and target the environment for change. Successful prevention will require public policy initiatives to enhance safe and easy access for physical activity and facilitate low-calorie food choices. Strategies for the prevention of obesity should involve public and private sector partnerships among community leaders, school administrators, employers, health care providers, and governmental agencies.