The examination and treatment of 547 patients with alimentary obesity revealed in them significant impairments of myocardial contractility, manifest hemodynamic disorders (in 65.5% of patients), marked changes in lipid metabolism (hypercholesterolemia, hypertriglyceridemia, hyperlipacidemia, hyperlipoproteinemia type IIa in 26,5%, type IIb in 14,5%, type IV in 32,5% of patients), as well as reduced activity of the T-immunity system, all these changes being prerequisites for the development of atherosclerosis, ischemic heart disease and essential hypertension. During examination of the patients' liver, fatty hepatosis was detected in 91.4%, chronic nonalcoholic steatohepatitis in 14% of patients, manifest shifts were found in their bile biochemical composition, leading to the development of cholelithiasis. The incretory dysfunction of the pancreas led to carbohydrate imbalance in 43%, and to diabetes mellitus in 7.5% of patients. Under the effect of the treatment (diet, exercise therapy, oxygenotherapy, hydrotherapy) conducted in the alimentary obesity patients, lessening of the pathologic process was observed in the heart, liver and pancreas, their functions being significantly improved. It has been concluded that normalization of the body weight in obese subjects is a measure preventing atherosclerosis, ischemic heart disease, essential hypertension, fatty hepatosis, steatohepatitis, cholelithiasis and diabetes mellitus.