The possible causes of constipation during weight loss are unreasonable diet, insufficient diet, etc. It can be treated by adjusting the diet, drinking enough water, and taking oral lactulose and other medications. 1. Adjusting diet: people with constipation can pay attention to eating more food rich in dietary fiber, such as fresh vegetables, fruits, soybeans, etc., as well as yogurt containing probiotics, etc. Dietary fiber can promote gastrointestinal peristalsis and increase the volume of fecal matter; probiotics can contribute to the balance of the microbial environment in the intestine, which in turn promotes intestinal defecation. Probiotics may produce side effects such as bloating. 2. Drinking enough water: If you don’t drink enough water, the feces in the intestines will dry up and the intestinal peristalsis will slow down, and then the symptoms of constipation will appear. Therefore, people who lose weight should pay attention to drinking enough water to replenish water for the body, and at the same time increase the water content of feces to promote defecation. 3. Medication: If the symptoms of constipation continue to be unrelieved, oral lactulose, bifidobacteria, mosapride citrate and other drugs can be taken to promote defecation. Weight watchers who suffer from constipation are advised to go to a regular hospital to find out the cause and get treatment if necessary.