The reasons why thin people have fatty liver are as follows: first, malnutrition, it is generally believed that overnutrition and obesity are the causes of fatty liver, but malnutrition can also cause fatty liver, for example, people who lose weight through diet control, so that weight loss, wasting, but at the same time accompanied by malnutrition, will also lead to fatty liver. Long-term alcohol drinkers can also cause malnutrition, because alcohol is a high-calorie food, after eating alcohol will have a feeling of fullness, which will cause loss of appetite, affecting other food meals, so there will be malnutrition, so a lot of alcohol drinkers will show thin, large abdomen, thin limbs and bones. Second, abnormal lipid metabolism, genetic factors or malnutrition will cause abnormal lipid metabolism, causing fatty liver, in addition to genetics can also cause fatty liver.