MEDICAL MANAGEMENT OF OBESITY

Overweight and obesity is the most common medical problem seen in primary care practice, affecting over 60% of adults and 15% of adolescents. 1, 2 Obesity, along with diet and physical inactivity, is estimated to be responsible for approximately 400, 000 preventable deaths per year and is expected to soon rival cigarette smoking as the most important public health concern. 3 The etiology of obesity is multifactorial, brought about by an interaction between predisposing genetic and metabolic factors and a rapidly changing environment. Interactive influences include social, behavioral, physiological, metabolic, cellular, and molecular factors. The most exciting breakthroughs in obesity research over the past decade have come from our understanding of the metabolic processes that control body-weight regulation. It appears that multiple feedback loops exist between the central and autonomic nervous systems, the endocrine glands, and adipose tissue, which operate to adjust hunger, satiety, and energy expenditure. Weight maintenance is now considered to be governed by a combination of short-term mechanisms originating in the gastrointestinal (GI) tract and longer-term processes, which monitor total adipose mass involving feedback to the central nervous system (CNS). 4 Signals that provide short-term information about hunger and satiety include gut hormones, such as cholecystokinin (CCK), ghrelin, and peptide YY3-36 (PYY), and signals from the vagus afferent neurons within the GI tract that respond to mechanical deformation, macronutrients, pH, tonicity, and hormones. 5 Whereas ghrelin stimulates food intake, PYY produces satiety. Several recent reviews on the metabolic regulation of body weight and appetite control have been published. 6–8.