Endocrine dysfunctions in eating disorders (anorexia nervosa, bulimia nervosa) result from disturbed regulation of hypothalamo-pituitary-gonadal, hypothalamo-pituitary-adrenal, hypothalamo-pituitary-thyroid and hypothalamo-pituitary-GH-IGF1 axes as well as of altered peripheral endocrine metabolism. Some peptides of hypothalamic origin, as well as those secreted by the adipose tissue and gastrointestinal tract including pancreatic hormones, are involved in the control of appetite and satiety. These peptides play also an important role in the mechanism of hormonal secretion. Altered activity of these biologically active substances may lead to the disturbances in the regulation of energy and hormonal homeostasis.