The American Medical Association, the nation's largest physician organization, decided Tuesday to recognize obesity as a disease that requires a range of medical interventions for treatment and prevention. The decision was made at the group's annual meeting in Chicago. Experts in obesity have struggled for years to have obesity recognized as a disease that deserves medical attention and insurance coverage as do other diseases. Previously the AMA and others have referred to obesity as "a major public health problem." About a third of adults in this country are obese, which is roughly 35 or more pounds over a healthy weight.