[Old and new aspects of obesity]

Some decades ago clinicians accepted that, for a given height and weight, the amount of calories necessary to maintain a constant weight differed from one individual to another. There was no apparent explanation for these individual differences. Later, however, obesity was thought to be the consequence of overfeeding. We now know that in the obese subject diet-induced thermogenesis may be diminished. In the rodent, diet-induced thermogenesis occurs in brown adipose tissue and is triggered by thermogenine, a polypeptide which uncouples oxidative phosphorylation. It is probable that diet-induced thermogenesis in man is under the control of the autonomous nervous system and is probably also triggered by thermogenine. These new insights into the pathogenesis of obesity have as yet no therapeutic implications. The indications for weight reduction are discussed.