The main reasons for weight gain of belly bloating are cirrhosis, obesity and pregnancy, etc. The main reasons for weight gain are cirrhosis, obesity and pregnancy. 1. Cirrhosis: Due to the decline in liver function in patients with cirrhosis, the production of albumin decreases, resulting in a decrease in the osmotic pressure of the blood loss of water, water shunt to the abdominal cavity, the water can not be discharged in time, which may lead to the patient to appear in the symptoms of abdominal distension and weight gain. 2. Obesity: If you eat high-calorie, high-fat food for a long time, it may lead to excessive accumulation of fat in the abdomen, and the fat may also compress the intestines, resulting in slower intestinal peristalsis, and then the food stays in the intestines for a long time and is easily fermented into gas, which leads to the symptoms of bloating and weight gain. 3. Pregnancy: When a woman is pregnant, due to the continuous development of the embryo, the uterus gradually increase in size, progesterone may inhibit gastrointestinal peristalsis, which will lead to the symptoms of stomach enlargement, bloating and weight gain. Patients with a large stomach, bloating and weight gain are advised to consult a doctor in time for targeted treatment under medical guidance. Please do not take medication on your own to avoid delaying your condition.