In this symposium, we will focus on causes and consequences of obesity, and discuss policy approaches to address this epidemic. Obesity is a major health concern, not only in the United States and other industrial nations, but also in the developing world. Over 78 million US adults are obese – a staggering 35% of the adult population. Obesity-related morbidities include stroke, heart disease, type 2 diabetes and cancer; and contribute to an estimated annual medical cost of over $145 billion in the US alone. Despite recognition of obesity as a worldwide epidemic, no country has achieved significant decreases in obesity prevalence in the past three decades. Importantly, emerging data reveal complex biological mechanisms underlying this disease, dispelling the stigmatizing notion that lack of self-control is the sole determinant of body weight. Recently identified neurological and socioeconomic associations require deeper understanding in order to design and implement effective policies for reducing obesity and comorbid disease burden. The objective of this symposium is to connect researchers, policy experts and health professionals, with the goal of exploring evidence-based approaches to address the obesity epidemic.