Roughly two thirds of U.S. adults are overweight or obese. Obesity increases the risk of hypertension, type 2 diabetes mellitus, hyperlipidemia, heart disease, pulmonary disease, hepatobiliary disease, cancer, and a number of psychosocial complications. Physicians often feel unprepared to handle this important problem. Practical office-based strategies include: (1) making recommendations for assisted self-management, including guidance on popular diets, (2) advising patients about commercial weight-loss programs, (3) advising patients about and prescribing medications, (4) recommending bariatric surgery, and (5) supplementing these strategies with counseling about lifestyle changes using a systematic approach. Family physicians should provide basic information about the effectiveness and safety of popular diets and commercial weight-loss programs, and refer patients to appropriate information sources. Sibutramine and orlistat, the only medications currently approved for the long-term treatment of obesity, should only be prescribed in combination with lifestyle changes. Bariatric surgery is an option for adults with a body mass index of 40 kg per m(2) or higher, or for those with a body mass index of 35 kg per m2 or higher who have obesity-related comorbidities such as type 2 diabetes. The five A's behavioral counseling paradigm (ask, advise, assess, assist, and arrange) can be used as the basis for a systematic, practical approach to the management of obesity that incorporates evidence for managing common obesity-related behaviors. (Am Fam Physician. 2010;81(12):1449-1455. Copyright (C) 2010 American Academy of Family Physicians.)