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Cystic Fibrosis

Contributors: Barbara Gordon, RDN, LD and Sarah Klemm, RDN, CD, LDN

Published: September 14, 2020

Reviewed: January 05, 2023

Child with cystic fibrosis | Cystic Fibrosis
KatarzynaBialasiewicz/iStock / Getty Images Plus

Most people with cystic fibrosis, or CF, are diagnosed by the age of two years old. CF is a genetic condition that causes mucus to collect in the lungs and around the pancreas. A buildup of mucus in the lungs can cause breathing problems. Lung infections are common for those with CF. In the digestive tract, the buildup of mucus affects digestion, which could lead to malnutrition. The mucus impacts a person's ability to absorb nutrients found in foods, especially fat and fat-soluble vitamins.

Individuals with CF need to pay careful attention to their eating habits. During childhood, nutritional status is key for overall health and survival. Lung infections and difficulties absorbing nutrients can affect growth. They may also make it challenging to maintain a normal body weight. The doctor might prescribe enzymes to take with meals and snacks that help to digest foods. Different treatments or other health conditions, such as diabetes or liver disease, may also influence foods and amounts that are recommended.

Registered dietitian nutritionists, or RDNs, create meal plans for children and adults with CF. Their recommendations are tailored to individual needs. Many individuals with CF need more calories, sodium, protein and fat when compared to their peers without CF, as well as vitamin and mineral supplements.

Calories and Fat

RDNs calculate calories based on a person's age, sex, activity level and health status. In children, growth needs are also important considerations. For both children and adults with CF, calorie needs may be 10 to 100% higher than those of a similar person without CF. To help get enough calories, people with CF may need to eat smaller, more frequent meals and snacks or focus on foods that add a lot of calories in small amounts, such as whole fat dairy products and healthy sources of fat.

In the past, a “high-fat” diet was prescribed for many individuals with CF. However, advances in treatment may help individuals with CF maintain or even gain weight.

Therefore, RDNs can help to determine the amount of fat and other nutrients an individual needs and develop a healthy eating plan based on their individual food preferences and culture.

These are a few common ways to include extra calories from fat:

  • Drinking whole milk or using it to make smoothies
  • Eating full-fat yogurt
  • Adding cheese to egg dishes, sandwiches, burgers and steamed vegetables
  • Mixing butter or cheese into mashed potatoes
  • Using cream to make sauces and puddings
  • Adding olive oil to pasta dishes or drizzling it over salads and grains, such as rice and quinoa
  • Dipping bread in olive oil
  • Choosing regular dressings instead of light, lite or diet salad dressings
  • Selecting fatty fish, such as salmon or mackerel, when having seafood
  • Adding avocado to salads and sandwiches or smoothies
  • Eating chips with guacamole
  • Snacking on trail mix with a variety of nuts and seeds
  • Spreading toast with peanut, almond or cashew butter

Balanced Eating Plans

A regular eating pattern that includes three meals per day and snacks, as needed, to meet calorie and protein needs is important for people with CF. A well-balanced, healthy eating plan includes a variety of vegetables and fruits, whole grains, dairy products and protein foods. Getting enough protein is very important for those with CF. The RDN can help you figure out how much protein you need and suggest foods that are good sources of protein such as meats, eggs, soy-based foods like tofu and tempeh, seafood, nuts and beans.

Vitamins and Minerals

Vitamin and mineral needs are often different for people with CF. An RDN can design an eating plan that includes foods and beverages that help meet these needs.

For example:

  • Vitamins A, D, E and K. The inability to absorb foods high in fat can also lead to deficiencies in fat soluble vitamins. Fat soluble vitamins include vitamins A, D, E and K.
    • Dairy products, some fortified breakfast cereals, sweet potatoes and dark green leafy vegetables are all sources of vitamin A
    • Eggs, fatty fish, like salmon, and fortified dairy products are good sources of vitamin D
    • Vegetable oils, nuts, and seeds are packed with vitamin E
    • Green leafy vegetables are the best sources of vitamin K
  • Calcium: Individuals with CF are at a higher risk of osteoporosis, or the weakening of the bones. This can increase the risk of bone fractures. An RDN can provide a list of foods that are good sources of calcium such as:
    • Milk, yogurt, and cheese
    • Calcium-fortified 100% fruit juices and soy beverages
    • Salmon with soft bones
    • Collard greens and kale
    • Sodium: Sodium is an electrolyte needed for muscle and nerve function. Individuals with CF lose a higher-than-normal amount of sodium in their sweat. Seasoning foods with salt can help increase sodium intake.
    • Iron: Many factors can influence an iron deficiency, which is common in people with CF. Foods providing a good source of iron include fortified cereals, oysters, some types of beans and lentils and beef. Other foods that contain iron in smaller amounts include dark green leafy vegetables.
    • Zinc: Another mineral that may result in a deficiency and helps to fight infection and promote healing is zinc. It is found in some of the same foods as iron. For example, beans, shellfish and meats. Dairy products and eggs also may provide zinc.

    Since an individual with CF may not be able to get all the vitamins and minerals needed, they may require a supplement in a formulation that is specific to CF. Be sure to check with a health care provider before taking an over-the-counter vitamin and mineral supplement.

    The Academy of Nutrition and Dietetics has a searchable database of RDNs. Enter your zip code to find a list of RDNs in your area.

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