Context: Ghrelin is a peptide secreted mainly by stomach, which has the ability to stimulate appetite and food intake. Serum ghrelin concentration decreases rapidly after the meal, probably because of the concurrent increase in serum insulin. Anorexia nervosa (AN) is an eating disorder, which is characterized by high serum ghrelin concentration, however, regulation of circulating ghrelin by insulin in this disorder remains unclear. Objective: To estimate serum ghrelin concentration in the fasting state and after hyperinsulinemia in women with AN. Design and participants: We examined 19 women with AN, 26 lean healthy women and 25 women with overweight or obesity. Serum ghrelin concentration was measured in the fasting state and after euglycemic hyperinsulinemic clamp. Results: Insulin sensitivity was similar in AN and normal-weight women and was markedly decreased in the obese subjects. In fasting state, serum ghrelin was higher in AN in comparison with other groups (normal-weight, p=0.017; obese, p=0.0001) and in normal-weight in comparison with the obese (p=0.044). Hyperinsulinemia resulted in a marked decrease in serum ghrelin in AN (p<0.0001) and normal-weight women (p=0.002). The fall in serum ghrelin was higher in AN in comparison with other groups (normal-weight, p=0.0008; obese, p=0.0001) and was related to insulin sensitivity (r=0.24, p<0.05). In multiple regression analysis, only fasting serum ghrelin and the presence of AN were independent predictors of this fall. Conclusions: Women with AN have an increased suppression of serum ghrelin by hyperinsulinemia. This phenomenon might lead to an increased and more rapid feeling of satiety in AN.