appetite

Mechanisms controlling  are a potential target for weight loss drugs. Appetite control mechanisms seem to strongly counteract under eating, whereas, they appear weak to control over-eating. Early anorectics were fenfluramine and phentermine. A more recent addition is sibutramine which increases serotonin and noradrenaline levels in the central nervous system, but had to be withdrawn from the market when it was shown to have an adverse cardiovascular risk profile. Similarly, the appetite suppressant rimonabant (a cannabinoid receptor antagonist) had to be withdrawn when it was linked with worsening depression and increased risk of suicide. Recent reports on recombinant PYY 3-36 suggest that this agent may contribute to weight loss by suppressing appetite.
Given the epidemic proportions of obesity in the Western world, and the fact that it is increasing rapidly in some poorer countries, observers^[who?] expect developments in this area to snowball in the near future. Dieting alone is ineffective in most obese adults - and even obese adults who successfully lose weight through dieting, often put weight back on afterwards.