Eat less and eat more, but don't increase the amount of food per meal. Because most thin people have weak gastrointestinal function, eating too much at a meal often cannot be effectively absorbed, but it will increase the burden on the stomach and cause indigestion. You can change the number of meals per day to 4~5 times. Food is based on the principle of high digestibility, high protein and high calorie, and gradually increases the intake of various nutrients, such as chicken, fish fillets, vegetables, sea cucumbers, butter and cream. Eat whatever you want to promote appetite. At the beginning of the "fattening" plan, you can choose some delicious food you want to eat to stimulate your long-term tired appetite. It is suggested to buy some special recipes with beautiful pictures and cook all kinds of delicious food in various ways. Let the diet that is good for you be seen everywhere. Besides dinner, we should also eat some snacks in moderation. At ordinary times, you might as well put some snacks with certain calories within your reach, such as biscuits, raisins, mung bean cakes, sausage bread, whole milk powder and chocolate. Eat if you want. Eating with oranges, oranges and other fruits, or adding juice to whole milk powder, can help the body consume more calories. Avoid eating foods that are irritating, easy to produce gas and have too much crude fiber, because such foods are easy to make people feel full and reduce their food intake. Appropriate vitamins and trace elements can be supplemented when necessary; Or take some Chinese patent medicines for regulating the spleen and stomach, such as hawthorn pill and Zhusha Yangwei Pill. Don't eat too much at night, otherwise it will increase the burden on the stomach, which is not good for health and sleep, and is also bad for bodybuilding. Pay attention to control the intake of fat, and don't eat too much fatty food for short-term fattening effect, which will not only cause weight gain, but also cause diseases such as coronary heart disease. Some fattening products in the health care products market are generally uncertain and should be carefully selected.