First, eat more. Eat more foods rich in fat and carbohydrates (starch, sugar, etc.). Excess energy can be converted into fat and stored under the skin, making the thin body strong. Thin people with weak gastrointestinal function should eat more chicken, duck, fish and sheep liver and eat more fish, which is also easy to digest and absorb. To increase dietary intake, pasta is the most useful. Eat more carbohydrates, high-protein foods, vegetables and fruits. Eat a lot every day and eat whatever you can.
Appropriate supplements are also necessary. According to the constitution and doctor's advice, eat some ginseng, red dates, longan honey, etc. And do some diet therapy.
Then we should keep a good mood and exercise properly.