Weight gain should be gradual, including increased caloric intake, appropriate exercise, etc., and should pay attention to exclude the underlying diseases, etc.. 1, want to increase weight, should be more intake of food, including rich in carbohydrates, fat, protein, vitamins and other food, such as rice, eggs, all kinds of meat and vegetables, etc., usually between meals can be some meals such as nuts, milk, etc.. 2. Some aerobic exercise can be carried out appropriately to increase the proportion of muscle, which helps to increase weight. 3. In addition, attention should be paid to the presence of disease factors that affect weight. For example, hyperthyroidism, gastroenteritis, malignant tumors, etc., timely and appropriate treatment. If there is a phenomenon of low weight, you should go to the hospital in time for examination.