With prevalence approaching 20% in the United States, adolescent obesity has become a common problem for patients, parents, and clinicians. Obese adolescents may experience physical and psychosocial complications, as illustrated by the case of Ms K, a 14-year-old girl with a body mass index of 40. Unfortunately, the effectiveness of pediatric obesity treatment is modest in younger children and declines in older children and adolescents, and few interventions involving adolescents have produced significant long-term weight loss. Nevertheless, novel strategies to alter energy balance have shown preliminary evidence of benefit in clinical trials, including a diet focused on food quality rather than fat restriction and a lifestyle approach to encourage enjoyable physical activity throughout the day rather than intermittent exercise. Parents can have an important influence on weight-related behaviors in adolescents despite typically complicated emotional dynamics at this age, especially through the use of noncoercive methods. A key parenting practice applicable to children of all ages is to create a protective environment in the home, substituting nutritious foods for unhealthful ones and facilitating physical activities instead of sedentary pursuits. Other behaviors that may promote successful long-term weight management include good sleep hygiene, stress reduction, and mindfulness. Ultimately, the obesity epidemic can be attributed to changes in the social environment that hinder healthful lifestyle habits, and prevention will require a comprehensive public health strategy.