Obesity in evolutionary perspective

Man is the only primate without fur. Hence subcutaneous fat constitutes the only means of insulation. For an endothermic animal such as man, whose tissues are susceptible to temperature fluctuations, an efficient means of insulation provided by subcutaneous fat not only conserves energy but also facilitates thermal regulation. The development of physiological mechanisms for accurate thermal regulation may be the basis of man's relatively long life-span. Why Homo sapiens, alone among the primates, substituted fat for fur as insulation is not know, but one plausible explanation may be the adoption of a semi-aquatic style of living during evolutionary development. Whatever the reason, subcutaneous fat is an important organ, and the level of adiposity is subjected to fine control by sophisticated physiological mechanisms. Thus, in healthy individuals, body fat content is a reflection of physiological requirements, and dietary and other measures for weight reduction may be detrimental to health. The time has come for the formation of a Fat Liberation Movement.