There are many foods that are not easy to digest and cause constipation, which are mainly categorized as high sugar, high protein and high fat foods. 1. High-sugar foods: sweets are not only not easy to digest, but also easy to cause constipation, such as dairy products, bread and other osmotic diuresis caused by the body too much water from the urine, causing dry stools, which leads to the symptoms of constipation is not easy to digest. 2. high protein food: meat products are recognized as high protein-rich food, research has found that animal protein is difficult to be digested by the human body, excessive long-term meat products, but also directly affect the human intestinal peristalsis, intestinal peristalsis will be slowed down, thus causing constipation occurs. 3. high fat food: refers to the high fat content of food, such as high oil content of food, plant walnuts, sesame seeds, peanuts, fried food, animal offal, cream products. There are many other foods that are not easy to digest and cause constipation. In order to avoid the symptoms of not easy to digest and cause constipation, it is recommended to choose a light diet and eat more fresh vegetables and fruits.