2. Pay attention to protein and carbohydrate intake when exercising. At the same time, in order to prevent muscle growth, fat is also increasing. In addition to adequate nutrition, food needs less oil, less salt and less sugar. At the same time, eat less over-processed food and refined carbohydrates. Beef, chicken and fish are the first choice for muscle building. Apart from eggs, meat is probably the most accessible source of protein. Beef, chicken and deep-sea fish are all good health-building and muscle-building foods. Nutritional value of beef. Beef is rich in protein, and its amino acid composition is closer to the needs of human body than pork, which can improve the disease resistance of human body, and is especially suitable for people who grow up after surgery and illness, such as supplementing blood loss and repairing tissues. At the same time, beef is also rich in sarcosine, protein, zinc, magnesium, iron, potassium and other trace elements, as well as vitamins B6 and B 12.