ABSTRACT
Obesity has grown to epidemic proportions in the United States and around the world. Current estimates are that more than 30 percent of the US adult population is obese and as many as two-thirds of the population are overweight (Ogden, Carroll, et al. 2006; Ford, Li, et al. 2010). In addition, the obesity problem is not limited to
Introduction ............................................................................................................ 103 Epidemiology of Obesity .................................................................................. 103 Food Reward ..................................................................................................... 105 Food as a Dependence-Inducing Substance ...................................................... 106
The Reward DeŠciency Hypothesis ....................................................................... 107 D-amphetamine and Reward DeŠciency ........................................................... 107 Neurobiological Evidence for Reward DeŠciency in Obesity .......................... 107 Genetic Evidence of Reward DeŠciency in Obesity ......................................... 112 Transgenerational Obesity and Reward DeŠciency .......................................... 112 Central Modulators of Dopamine Signaling That Are Altered in Obesity ........ 113 Peripheral Signals Inœuencing Hedonic Aspects of Food Intake ...................... 114 Evidence Disputing the Reward DeŠciency Hypothesis in Obesity ................. 115
The Reward DeŠciency Hypothesis in Eating Disorders ....................................... 116 Binge-Eating Disorder ...................................................................................... 116 Bulimia Nervosa (BN) ...................................................................................... 118 Anorexia Nervosa .............................................................................................. 120
Conclusions ............................................................................................................ 122 Acknowledgments .................................................................................................. 123 References .............................................................................................................. 123
adults. The prevalence of overweight children has increased to more than 15 percent over the last several decades with more than 30 percent of children at risk for being overweight with a Body Mass Index (BMI) z-score greater than the 85th percentile (Ogden, Carroll et al. 2008). Because obesity not only is associated with a number of cardiovascular diseases and diabetes, but also is related to cancers, mental disorders, fertility, and orthopedic issues, the annual direct medical cost burden of obesity in the United States is estimated to be close to $150 billion in adults and another $14 billion in children (Hammond and Levine 2010).
