If you find yourself underweight, you should first check whether it is the potential influence of diseases, such as thyroid, diabetes, adrenal gland and digestive system diseases, which may easily lead to underweight. Only when the disease is eliminated can the fattening plan be implemented. In the case of adequate intake in protein, we should eat more foods rich in fat and carbohydrates (starch, sugar, etc). ). In this way, excess energy can be used.