Nutrition, essential for growth and development, helps fight infections, heal wounds and provide energy to play and exercise. Well-nourished CF patients grow better, have better lung function, and feel better than those who are malnourished. CF patients need extra calories because they use more energy breathing and fighting infections, and they may lose calories from malabsorption.

Malnutrition occurs when your body does not get enough calories to promote normal growth or maintain a healthy weight. It impairs your body's ability to fight infections, and causes growth failure, lack of appetite, and decreased energy. But malnutrition can be avoided.

Your body gets energy from food in the form of calories. Foods have different numbers of calories depending on whether they contain carbohydrates, protein or fat. Carbohydrates and protein have 4 calories per gram, but fat has 9 calories per gram. Eat a balanced diet rich in all food groups to receive enough calories to fuel the body for exercise and growth. People with CF need extra calories, about one-and-a-half times as much as a person without CF. This higher calorie diet can be achieved by including a liberal amount of fat in every meal.