Obesity and cancer.

Obesity has become the second leading preventable cause of disease and death in the United States, trailing only tobacco use. Weight control, dietary choices, and levels of physical activity are important modifiable determinants of cancer risk. Physicians have a key role in integrating multifactorial approaches to prevention and management into clinical care and advocating for systemic prevention efforts. This article provides an introduction to the epidemiology and magnitude of childhood and adult obesity; the relationship between obesity and cancer and other chronic diseases; potential mechanisms postulated to explain these relationships; a review of recommended obesity treatment and assessment guidelines for adults, adolescents, and children; multilevel prevention strategies; and an approach to obesity management in adults using the Chronic Care Model.