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Cystic Fibrosis: Diet and Nutrition

Medically reviewed by: Michelle Reed, RD, LDN

What Is Cystic Fibrosis?

Cystic fibrosis (CF) is a genetic condition that affects the body's epithelial cells. These cells are found in many places, including the sweat glands, lungs, and pancreas.

An error in the cells causes problems with the body's balance of salt and water. The body responds by making thick mucus, which blocks the lungs and sometimes other ducts and passageways, causing infections and breathing problems.

How Does Cystic Fibrosis Affect Nutrition?

The sticky mucus from cystic fibrosis can block normal absorption of key nutrients and fat in the intestines, causing:

  • poor digestion
  • slow growth
  • trouble gaining weight
  • greasy bowel movements

Why Do Some Teens Need Enzymes?

CF often causes a condition called pancreatic insufficiency. This means the enzymes made in the pancreas that digest fat, carbohydrates, and protein don't pass into the intestines as they should. So the body can't digest food normally.

Teens with pancreatic insufficiency might have problems with growth and weight gain. They also might have frequent and bad-smelling bowel movements. They'll need to take prescribed enzymes with meals and snacks to help them digest food and keep a healthy weight. A CF doctor will work with a dietitian to prescribe enzymes based on weight, growth, and bathroom habits.

If you take pancreatic enzymes in pill form:

  • Enzymes should be taken with all foods and drinks that have fat and protein.
  • Enzymes should never be chewed or crushed. They must be swallowed whole.
  • Enzymes are sensitive to temperature. Store in a cool, dry place. Avoid extremes in temperature, such as leaving enzymes in the car during the summer or winter months.
  • Consider taking an extra enzyme cap for large meals or fast food meals that are extra fatty.

What's a Healthy Diet for Someone With CF?

In the past, a healthy diet for someone with cystic fibrosis was high-calorie, high-fat, and high-salt. But new therapies make weight gain easier and life expectancy longer. So the focus of a healthy diet is changing. It's becoming more important to consider how diet can keep you feeling healthy as you grow older. Healthy diet choices can help prevent other conditions, such as heart disease or cancer, while improving your quality of life.

Here are some basics of a healthy diet:

  • Eat five servings per day of fruits and vegetables.
  • Include protein with meals and snacks.
  • Choose whole grains over refined grains.
  • Avoid sugary drinks like juice, soda, sweet tea, lemonade, etc.
  • Eat more homemade meals and less fast food or restaurant meals.

What's a Healthy Weight for Someone With CF?

A healthy weight for teens with cystic fibrosis is different for each person. Your CF team will talk a lot about body mass index (BMI). BMI is a way to measure if you are at a healthy weight (not underweight or overweight) by comparing your weight to your height. The goal for all teens with CF is to reach a healthy weight that supports healthy lungs. Talk to your CF doctor or dietitian if you have questions about your healthy weight goals.

What Extras Do Teens With Cystic Fibrosis Need?

Teens with CF have some specific nutritional needs:

Salt. Teens with CF lose more salt in their sweat than their peers. The dietitian may suggest adding extra salt to foods, eating salty snacks, and drinking sports drinks when teens exercise or spend time outdoors in hot weather.

Fat-soluble vitamins (vitamins A, D, E, and K). These vitamins are important for immune function, growth, and healing. They're absorbed along with fat. Most teens with CF have trouble digesting and absorbing fat, which means they may not absorb fat-soluble vitamins. Your fat-soluble vitamin levels will be checked once a year, and you might take a prescription CF-specific multivitamin.

Calcium. Teens with CF, especially those with pancreatic insufficiency, are at risk for osteopenia or osteoporosis (weak, brittle bones). Dairy products are good sources of calcium (and the full-fat varieties also are good sources of fat and calories). If you don't drink cow's milk, consider trying a milk alternative that is fortified with calcium.

Calories. Some teens with CF need extra calories to grow healthy and strong. The extra calories should come from a well-balanced, healthy diet.

How Can Teens Reach High-Calorie Needs?

Some teens with CF need more calories than their peers. The best way to meet these calorie needs is by eating a well-balanced diet, but adding extra calories with added fat. Here are some tricks for adding extra calories to your day:

  • Add extra butter or oil to pasta, rice, potatoes, or cooked vegetables.
  • Pair raw vegetables with salad dressing or hummus.
  • Top salads and sandwiches with avocados or guacamole.
  • Grill sandwiches in butter or margarine.
  • Add a splash of heavy cream to milk, oatmeal, smoothies, or cream-based soups.
  • Focus on high-calorie snacks. Try trail mix, peanut butter and banana sandwiches, full-fat yogurt with granola, or cheese crackers.

Why Do Some Teens Need Nutrition Supplements or Tube Feedings?

Some teens with CF may have trouble gaining weight from a high-calorie diet alone. A doctor or dietitian may recommend adding nutrition supplements to your diet. Nutrition supplements are calorie-rich drinks that also have protein, vitamins, and minerals. For some teens, this added source of calories is enough to improve weight gain.

If a high-calorie diet and nutrition supplements are not enough, a doctor or dietitian may recommend tube feedings. These feedings, done through a tube into the stomach, are often given at night for extra calories. These overnight feedings leave teens with CF free to enjoy normal meals and activities during the day.

Making the decision to get a feeding tube can be hard, but many teens and families express relief afterward. Tube feedings can help teens gain weight, while easing the stress and conflict around food and eating. Having a tube put in for the feedings usually is a simple procedure that doesn't need extensive surgery or a long hospital stay.

What Else Should I Know?

Meeting the unique nutrition needs of CF isn't always easy. Work with your team to set nutrition goals that you can reach. If talking about food or nutrition feels stressful, consider working with the psychologist on your CF team. They can help you manage the emotions linked to how you eat.

Besides the right diet, exercise can help support better lung health, mood, and quality of life. Talk to your doctor or the physical therapist on your CF team about the right kind of exercise for you.

Medically reviewed by: Michelle Reed, RD, LDN
Date reviewed: January 2020