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.
Primary nutritional deficiency is one of the most basic types of malnutrition, and occurs in people who do not have enough nutrients in their diet. According to the Kidâs Health website, malnutrition is one of the most prevalent causes of infant mortality, with about 10 children dying of malnutrition each minute.