It is only within the last 10 years that the potential contribution of serotonin (5-HT) to the control of food intake and body weight has even been considered. This notion was put forward only after the accumulation of a great deal of evidence pointing to the influence of catecholamines on energy regulation. Research on 5-HT is currently being undertaken within a framework in which the extreme complexity of food intake control and body weight regulation is being increasingly recognized. This, in turn, has contributed to the abandonment of the somewhat simplistic view that obesity is a solitary homogeneous disease for which only a defect of total food intake has to be considered. Today the concept of obesity as a single clinical entity is being replaced by the concept of several forms of obesity, corresponding to different pathological syndromes and involving complex etiologies and mechanisms. Accordingly, when studying energy input, we must consider not only total intake but also the qualitative patterns that could lead to hyperphagia: patterns of eating behavior (binging, snacking, the sizes and distribution of meals); food choice, particularly the consumption of carbohydrates, fats, and protein; environmental events, including stressors and other emotional stimuli; the hedonic value of food (its perceived pleasantness and satisfaction); and eating sensations and the perception of hunger and fullness.In conjunction with energy input, it is also necessary to consider energy utilization, peripheral metabolism, and their possible modifications in different types of obesity. Such considerations have led to the recognition that body weight regulation is the result of the complex interaction of both central and peripheral mechanisms. These mechanisms involve a variety of neurochemical systems, including catecholamines, serotonin, probably GABA, and a number of neuropeptides (particularly beta-endorphin, a kappa opiate system, CRF, and neuropeptide Y ) . These may be active in both the central nervous system and peripheral tissues. The treatment of obesity (and of eating disorders) should therefore be considered qualitatively, and should involve a search for selective therapeutic approaches.Within this framework, the analysis of serotonin systems should lead to a clearer definition of the role of 5-HT, not only in the control of food intake, but also on general metabolism and, ultimately, on body weight regulation. This, in turn, will lead to both a better understanding of the physiology and pathophysiology of energy regulation, and will also bring considerable therapeutic benefit through the search for advanced forms of serotoninergic treatment and the understanding of their mode of action.
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ANNALS NEW YORK ACADEMY OF SCIENCES
SEROTONINERGIC COMPOUNDS AND WEIGHT EVOLUTIONThe contribution of serotonin to weight regulation is now fully recognized: stimulation or manipulation that enhances serotonin tone can lead to weight loss.On the other hand, destruction or inhibition of serotoninergic pathways in animals lead...
