The epidemiology of obesity.

Obesity has received considerable attention as a major health hazard because of the increase in the prevalence of obesity not only in the United States but also in several other countries worldwide. Obesity is caused by an interaction of environmental factors, genetic predisposition, and human behavior, and is associated with an increased risk of numerous chronic diseases, from diabetes and cancers to many digestive diseases. The obesity epidemic exerts a heavy toll on the economy with its massive health care costs. This article describes some of the epidemiologic features of obesity, including global prevalence, secular trends, risk factors, and burden of illness related to obesity with special emphasis on obesity trends in the United States. Published by Elsevier Inc.