Malnutrition in children refers to a disease in which the body cannot grow and develop normally and maintain normal metabolism due to insufficient nutrition or malabsorption. Supplementary nutrition is the key to treat malnutrition in children. The following are some common supplementary methods:

1. Increase food intake: reasonably arrange food intake according to children's age, height and weight, and increase the intake of nutrients such as protein, carbohydrate and fat.

2. Vitamin and mineral supplements: Children can take vitamin and mineral tablets orally, but pay attention to dosage and usage to avoid excessive or improper use.

3. Give high-energy foods: High-energy foods such as milk, eggs, meat and beans can help children gain weight and improve their nutritional status.

4. Nutritional support therapy: For children with severe malnutrition, intravenous infusion can be used for nutritional support therapy to restore health quickly.

5. Strengthen physical exercise: Appropriate physical exercise can promote appetite, digestion and absorption, and help improve children's nutritional level.