Nutrition rules with cystic fibrosis

Research shows that a good nutritional condition leads to better lung function and better resistance to respiratory infections. A good diet also helps to build reserves that can be used in case of infection or weight loss.

Food is the fuel that makes our engine run

Our bodies need energy to function: to run, learn, grow, breathe, and fight disease. We get this energy from food. As you already know, digestion goes worse in people with cystic fibrosis. This is why they cannot get enough energy from the food they eat, even when taking pancreatic enzymes. In addition, they need more energy than others in order to fight lung infections and because breathing requires a great deal of effort, and therefore requires more energy.

The amount of energy provided by food is expressed in kilocalories (kcal). It is therefore particularly important that the diet of people with cystic fibrosis contains a lot of calories. This means that a child or young person with cystic fibrosis must drink and eat foods that are higher in calories than an individual of the same age in order to grow as harmoniously as possible. Energy needs depend on a variety of factors: the extent to which the pancreas is still functioning, age, gender, height and weight, health status, activities, and lung function. It goes without saying that after playing all morning outside, a child will have a greater appetite than if they spend all day inside watching TV or reading. The dietitian at your clinic can calculate how much extra energy is needed for each child and adult with cystic fibrosis.

If the weight and height change well, there is no need to worry

Right from the start, and with good reason, the importance of good nutrition is emphasized. But eating doesn't have to be a problem when you have cystic fibrosis! Weight and height are evaluated according to the evolution of the growth curve. During each check at the cystic fibrosis clinic, weight and height are measured and recorded on this curve. For children, this measure is often expressed in percentiles, with the average goal being to reach the 50th percentile: this means that 50% of children of the same age have a higher weight and height, and 50% of children have a lower weight and height. For adults, we talk about BMI or body mass index, a measure that combines height and weight.

Doctor and dietitian review the growth curves with the patient and family, and in light of the results, they reassess food intake if necessary. If weight and height change well, you don't have to worry about eating! On the other hand, if weight and height do not change positively, it will be necessary, together with the medical team, to examine the possibility of changing something in the patient's diet and to ask whether other elements play a role, in order to try to find a solution.

The prescribed diet: rich, varied and tasty

Lipids are the nutrients that contain the most energy; as such, they are particularly important in the diet of patients with fibrocystic fibrosis. They contain 9 kcal per gram, and represent the main source of essential fatty acids and fat-soluble vitamins.

Carbohydrates include sugars and starches under the same name. They are essential fuels for our body and provide 4 kcal per gram. Foods that contain starches, such as gray bread and potatoes, will be preferred over sugars because they contain more vitamins, minerals, and fiber. Sugars that are used too much can restrict appetite.

Proteins represent the building blocks that build our body. Our skin, muscles, and heart are made up of proteins. So we need it to grow. Like carbohydrates, proteins provide 4 kcal per gram.

In the diet of patients with cystic fibrosis, salt plays an important role, because in them, salt loss is very great. They must therefore make up for this lack by drawing salt from food.

Fiber also plays an important role in the proper functioning of the large intestine, and helps to avoid an occlusion. So fiber is part of a healthy diet. This is why it is imperative to consume vegetables, fruits, gray and wholewheat bread, and potatoes. Be aware that peels also contain a large amount of fiber.

Variety on the menu

Food should not only provide enough energy (and be appetizing)! It should also contain a range of nutrients. Your body needs a little bit of everything to function properly. It is therefore necessary to provide a sufficiently varied menu every day. For example, if you eat fries every day, you are likely to gain enough energy, but not enough vitamins, minerals, or antioxidants. It is therefore necessary to consume different dairy products on a daily basis and alternately meat, chicken, fish and eggs. Dairy products and eggs not only provide proteins, but also fat-soluble fats. Oily fish provides a lot of energy as well as essential fatty acids to the body. In addition to fats and proteins, meat also provides iron and vitamin B12. Vegetables and fruits do not contain a lot of energy, but they are rich in vitamins, minerals, and fiber, which are essential for all of us.

Every human needs to drink enough, but it's even more important for cystic fibrosis patients, who need lots of moist elements.

Indeed, the loss of moisture through mucus, sweat and stools is significant. In addition, cystic fibrosis patients consume foods that contain a lot of protein, and without adequate water intake, this can lead to kidney problems. It is therefore necessary to increase water intake in order to facilitate the elimination of mucus and to limit the risk of intestinal obstruction (constipation). In case of high heat, sustained physical effort, fever, vomiting, diarrhea and constipation, it is essential to drink more. Water, fruit juices, soups, and broths can help us to store enough moisture in the body. Whole milk is a great drink, which contains a lot of fats and vitamins. To a certain extent (preferably not before or during a meal), you can also consume sodas such as cola and lemonade. But soda contains a lot of sugar, which reduces appetite, at the expense of other essential nutrients. Too much cola can lead to decalcification. When drinking water, fruit juice, and soda, no pancreatic enzymes are required; however, for drinks that contain fat, they should be taken.

Vitamins

When you have cystic fibrosis, fats are difficult to digest; the same is true for fat-soluble vitamins A, D, E and K. A supplement containing these vitamins is therefore prescribed to cystic fibrosis patients. It has long been known that vitamin D plays a decisive role in bone formation. Given that the
Cystic fibrosis patients are at increased risk of conditions such as osteoporosis. It is especially important that they take enough vitamin D. Studies have also shown that the risk of flu or cold decreases when taking vitamin D. In addition, recently, research has also shown that this vitamin also reduces the inflammatory phenomenon. All of these reasons confirm the need for cystic fibrosis patients to take adequate amounts of vitamin D. The new American guidelines suggest testing vitamin levels, which are often too low, at the end of winter. Some vitamin preparations can meet vitamin D needs. Sunlight also provides the body with additional vitamin D. Like vitamin D, vitamin K is also very important for skeletal health, but vitamin K is best known for its role in blood coagulation. A lack of vitamin K can lead to airway bleeding. In addition to vitamins A, D, and E, vitamin K therefore also has a place in vitamin preparations prescribed in case of cystic fibrosis.

Complementary feeding and nutritional supplements

If, despite a particularly rich and varied diet, and the intake of the necessary pancreatic enzymes, a good dietary condition is not there, it is sometimes advisable to use food supplements. There are a series of caloric drinks ready for consumption, some of which provide up to 400 kcal per bottle. You can also buy milkshake formulas in the form of small packets of powder that can be diluted in whole milk and contain up to 600 kcal per serving. Some children and young people with cystic fibrosis prefer milk drinks and milkshakes, others prefer fruit-based drinks. Small drinks available in supermarkets, such as some small fruit cheeses and puddings, contain just as many calories and sometimes even more calories. Normally, the amount of kilocalories and nutrients is stipulated on the package. You can also make small energy drinks yourself (ask your dietitian for advice on this). It is necessary to take pancreatic enzymes with all dietary supplements, even those based on fruits.

Attention: all these small drinks are intended to supplement the diet, and not to replace the usual meals. If you notice that you or your child are eating less and less at mealtimes, these supplements are not a good solution! Studies show that dietary supplements mainly have a positive effect in certain specific cases, such as during an exacerbated period of the disease, or when the patient needs to gain strength, or when the stress generated by food and eating behaviors become difficult for the family to bear.

In the event that the usual diet and dietary supplements are no longer sufficient to provide the necessary energy, or if it becomes useful for one or another reason to obtain additional energy, one can resort to nocturnal tube feeding (a thin pipe connected directly to the stomach).

Dr Karleen De Rijcke
Director General, Belgian Cystic Fibrosis Association
Bruxelles, Belgium

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