Obesity, defined by the World Health Organization (WHO) as body mass indices (BMI) >=30 kg/m2, respectively1 is associated with increased incidence of hypertension, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and certain cancers.2, 3 Moreoever, the prevalence of obesity in the United States has doubled in the past three decades, from 15% in 1976–1980 to 33% in 2003–2004.4 Correspondingly, there has been a marked increase in risk for premature death due to obesity-related disease, and the relative contribution of obesity-attributable mortality to total deaths in the U.S. rose substantially between 1990 and 2000.5, 6
