1. Leptin is generally thought to play a key role in the regulation of eating. However, its real role in human eating behaviour is still poorly known. Therefore, the role of leptin in the regulation of eating was examined in obese binge- and non-binge-eating women during exposure to food and food-related stimuli.
2. Eleven binge- and ten non-binge-eating obese women took part in the study. In addition to serum leptin, serum insulin, non-esterified fatty acids, plasma glucose, salivation, the feeling of hunger and the desire to eat were repeatedly measured during the experiment.
3. Serum leptin levels did not differ between the binge- and non-binge-eating women. Neither were leptin levels associated with the feeling of hunger or the desire to eat food, nor with the amount or composition of food eaten. During food exposure leptin levels did not change, whereas at the same time serum insulin levels increased and serum non-esterified fatty acid levels decreased. The change in salivation during food exposure was inversely associated with the fasting leptin level.
4. This study indicates that serum leptin does not play a role in the regulation of eating in obese women, at least not in the short term. Furthermore, leptin levels are not different in obese binge-eating women as compared with obese non-binge-eating women. Interestingly, high fasting leptin levels may be associated with a decreased salivation response in the presence of food and food-related stimuli.