Recent progress in the field of energy homeostasis was triggered by the discovery of adipocyte hormone leptin and revealed a complex regulatory neuroendocrine network, which precisely regulates appetite. Discovery of ghrelin, a novel hormone derived from the stomach, has illustrated the relationship of the stomach and hypothalamus which is a crucial missing link in the regulation of energy balance, growth and coordinated gastrointestinal function. The discovery of ghrelin opens new perspectives of research with potential therapeutic relevance in patients with gastrointestinal, metabolic, endocrine and other diseases.