Cholelithiasis is a condition in which stones appear anywhere in the bile ducts, either in the gallbladder or in the bile ducts. In the obese population, more people do suffer from cholelithiasis than in the general population. When weight exceeds 50% of ideal body weight, the number of gallstones with clinical symptoms can increase as much as six times! Patients with gallstone disease can be asymptomatic when the disease is mild, and can manifest as loss of appetite, discomfort and even pain in the right upper abdomen when it is slightly more severe, which is significantly worse after eating foods that are more oily. When stones block the bile ducts or the mouth of the gallbladder, they may cause acute cholecystitis, with unbearable abdominal pain radiating to the right side of the lower abdomen, accompanied by vomiting and fever, and even life-threatening. According to the composition, gallstones can be divided into two main types: cholesterol stones and bile pigment stones. Obese people are mainly prone to cholesterol stones. The main way to eliminate cholesterol from the body is to dissolve it in the bile and excrete it through the bile duct to the intestine and then out of the body through the feces. If there is too much cholesterol in the body or if the composition of the bile changes, cholesterol will be deposited in the bile duct and form stones. Obese people are prone to cholesterol stones because of two reasons: on the one hand, obese people have much more cholesterol in their bodies than ordinary people. Obese people often love to eat a diet high in cholesterol, plus the body’s own synthesis of endogenous cholesterol is also more, every increase of 10 kg of fat tissue, will synthesize about 200 grams of cholesterol per day, equivalent to the cholesterol contained in an extra egg! On the other hand, the content of phospholipids and bile acids in the bile of obese people is also changed, which makes cholesterol in the bile easily reach the state of supersaturation, so it is deposited into the bile duct and forms stones. Therefore, if obese people want to suffer less from gallstone disease, or should eat less high cholesterol food, at the same time must actively reduce weight.