A teleological view of obesity, diabetes and hypertension.

1. The current worldwide epidemic of obesity and its major complications, namely type 2 diabetes and hypertension, is well documented. The present mini-review develops the thesis that 'thrifty' metabolic traits, evolved in the setting of intermittent famine, contribute to the obesity pandemic. 2. These thrifty traits, namely a decreased capacity for dietary thermogenesis and an increased resistance to insulin-mediated glucose uptake in skeletal muscle, would prolong survival during famine but predispose to obesity and diabetes in the face of abundance. The regulation of dietary thermogenesis by the sympathetic nervous system also explains the well-established association between obesity and high blood pressure. 3. These observations provide a deep-seated rationale for the efficacy of lifestyle interventions in the treatment of obesity and its complications and may also provide a predicate for the development of new therapeutic strategies aimed at neutralizing the impact of these thrifty traits. Such strategies may entail, for example, therapeutic agents that enhance metabolic rate during low-energy diets, thereby reversing the physiological impediment imposed by suppression of the sympathetic nervous system.