What are the adverse effects of malnutrition on children with prediabetes 1, growth and development lag. Malnourished children have slow or no weight gain, height and head circumference growth, movement, language, cognitive ability are behind the normal children of the same age, etc. 2, affect the wound healing ability and immune function. Children with combined malnutrition are more susceptible to infection, and infection will aggravate malnutrition and cardiac insufficiency, forming a vicious circle. Children with severe precocious heart disease can die from infection before surgery. Severe malnutrition can also damage the myocardium and lead to cardiac failure; reduce the stress response to cardiac surgery, increase the chance of post-surgical infection, prolong hospitalization, and increase perioperative complications and mortality. Fourth, how to assess the nutritional status of the child The most common and simplest method is to measure the child’s height and weight, where weight is more sensitive than height. Other immunological and biochemical parameters such as arm diameter, skin fold thickness, blood albumin, prealbumin, transferrin, serum insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) are also measured. Parents can use the weight of a normal child of the same age as a reference standard to roughly assess the degree of malnutrition in their child. If the weight of the normal value of 80％-90% is mild malnutrition, between 70%-80% is moderate, less than 70% of normal is severe malnutrition. Five, how to prevent and treat malnutrition in children with precocious heart disease 1, early prevention and early intervention: from the child’s diagnosis of precocious heart disease, until the perioperative or interventional period and after treatment, parents and treating physicians should pay active attention to the child’s feeding problems and nutritional status. Early surgical or interventional treatment: The impact of precocious heart disease on the child’s feeding and development is an important reference factor in determining the timing of treatment. Once the child shows the aforementioned feeding difficulties and slow or no weight gain, it suggests that conservative treatment or medical treatment is not effective and surgical or interventional treatment should be performed early. Usually, after surgery or intervention, the child will eat significantly more and gain weight rapidly, which is called “catch-up growth”. However, children born with low birth weight, mental deficiency, residual heart malformation or palliative surgery may have limited recovery of nutritional status after surgery. 3. Active nutritional therapy: The main method is to provide the child with a high-calorie and high-protein diet that exceeds the conventional amount, as long as the child’s stomach and intestines can tolerate it. For example, for breastfed infants, formula or special breast milk additives can be added to breast milk to increase the calories to 80-90 kcal/100ml, and for non-breastfed infants, high calorie formula with 80-100 kcal/100ml can be used for feeding. Children with combined cardiac insufficiency and gastroesophageal reflux can be fed in small amounts and several times, while reducing or controlling water intake to reduce the cardiac volume load. For children of toddlers and children’s age, encourage the intake of foods containing high protein, high carbohydrate and high fat, drink more milk as appropriate, and avoid or reduce the consumption of non-caloric beverages. 4, the child to cultivate and establish good feeding habits: parents of children with precocious heart disease need to pay more love and patience than the average parent, take the initiative to learn and understand the feeding and nutrition knowledge, consciously train their children to establish good eating habits, find out the feeding tricks that suit their children’s temperament, so that their children do not eat partially, not picky eaters. 5, other: such as medication to treat cardiac insufficiency and gastroesophageal reflux, vaccination to prevent respiratory infections, etc.