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.
In more wealthy industrialized nations malnutrition is usually caused by: 1  Poor diet-if a person does not eat enough food, or if what they eat does not provide them with the nutrients they require for good health, they suffer from malnutrition. 2  Poor diet may be caused by one of several different factors.alnutrition is a broad term which refers to both undernutrition (subnutrition) and overnutrition. Individuals are malnourished, or suffer from undernutrition if their diet does not provide them with adequate calories and protein for maintenance and growth, or they cannot fully utilize the food they eat due to illness.