Scheme of the human fat metabolism as supposed according to our hypothesis. Human pancreatic lipase (HPL) hydrolyzes nutritional fat. The recently discovered adipose triglyceride lipase (ATGL) is rate limiting for the mobilization and storage of adipose. We assume that ATGL is regulated allosterically in the way we demonstrated herein. Irrespective of food supply this regulation mechanism keeps the concentration of the products of hydrolysis constant and maintains energy homeostasis. Hormone-sensitive lipase (HSL) is of minor importance.