In the bile of patients with alimentary obesity, the content of primary (cholic) bile acids is reduced, that of secondary (deoxycholic) acids is increased, and the quota of glycine-bound cholates is lowered. This points to the distress of the cholate-synthesizing, glyco-conjugating, and hydroxylating function of liver cells. In addition, the bile of obese persons is characterized by a low content of free fatty acids associated with an increase in the amount of total lipids, glycerides, and phospholipids. The treatment of obesity by the subcaloric diet and graded physical exercise brings about positive changes in the content of cholic and deoxycholic acids in the bile and gives rise to the enhanced excretion of all lipid fractions, cholesterol in particular, with the bile to the intestine, thereby raising the bile lithogenic potential.