1 Underweight (BMI below 18.5): If you were underweight for your height you should gain 28 to 40 pounds. 2  Overweight (BMI of 25 to 29.9): If you were overweight for your height you should gain 15 to 25 pounds. 3  Obese (a BMI of 30 or higher): If you were obese for your height you should gain between 11 and 20 pounds.
In the UK, the most common causes of malnutrition in children are long-term health conditions that: 1  cause lack of appetite. 2  disrupt the normal process of digestion. 3  cause the body to have an increased demand for energy.
Symptoms of malnutrition in children include: 1  Growth failure. This may be manifested as failure to grow at a normal expected rate in terms of weight, height or both. 2  Irritability, sluggishness and excessive crying along with behavioral changes like anxiety, attention deficit are common in children with malnutrition.