People with cystic fibrosis require a much higher energy intake than normal to provide sufficient kilojoules for their needs, and to compensate for poor absorption caused by a lack of digestive enzymes.
The fact that the sticky mucus secreted by these individuals blocks the ducts that transport enzymes and bile to the intestines, will also hamper the absorption of all other nutrients and increase the requirement for protein, easily digestible fat, vitamins and minerals.
In an excellent update on cystic fibrosis and nutrition, published by the Nutrition Information Centre of the University of Stellenbosch (NICUS), the authors point out that "nutrition management and care of CF (cystic fibrosis) involves increasing and maximising dietary intake, minimising malabsorption and maldigestion, monitoring of micronutrients (vitamins and minerals) and adapting eating habits to treat the complications associated with CF".
This involves intensive input from an expert such as a clinical dietician. Cystic fibrosis is one disease where the sufferer benefits greatly from individual diet therapy provided by a clinical dietician.
So if you, or a member of your family, have been diagnosed with cystic fibrosis, it's essential that you should consult a clinical dietician on a regular basis. The dietician will not only work out a diet that will make provision for the added nutrient requirements outlined above, but also monitor development in children to ensure that their growth isn't stunted due to a lack of essential nutrients.
Dietary supplements (liquid high-energy, high-protein foods)
Cystic fibrosis can increase the daily dietary requirement to such an extent that those suffering from the condition find it impossible to obtain all the nutrients they need from standard foods.
Any flare-up of the disease, such as an attack of pneumonia, will not only increase nutrient requirements drastically, but also suppress the individual's appetite. This is when a liquid dietary supplement can play an important role.
You can also make your own high-energy, high-protein liquid supplements by using full-cream milk, ice cream, sugar or honey, fruit juice, full-cream milk powder and eggs.
a) Avocado smoothie
Scoop flesh out of a whole, ripe avocado and liquidise in a blender with two tablespoons of sugar or honey and two tablespoons of lemon juice (to prevent browning). Add one cup of full-cream milk and two tablespoons of full-cream milk powder (to increase the protein content). Blend. Add additional full-cream milk until the consistency is easy to drink. Chill in the fridge and serve cold with a pinch of nutmeg or a sprig of peppermint. Add more honey or sugar to taste.
b) Strawberry smoothie
Wash and de-hull half or one punnet of fresh strawberries. Liquidise in a blender with two tablespoons of sugar or honey. Add one cup of full-cream milk, two to three scoops of ice cream (vanilla or strawberry flavour) and one whipped-up egg (whole or white). Blend untill smooth. Add additional sugar or honey for flavour. Chill and serve cold with a sprig of peppermint.
Beat one raw egg well and add one cup of full-cream milk, one to two tablespoons of sugar or honey, three tablespoons of full-cream milk powder, a pinch of salt and three to four drops of vanilla essence. Blend. Strain if necessary to remove any pieces of unbeaten egg. Chill and serve cold with a sprinkle of nutmeg, or add cacao syrup or other flavourings.
The golden rule
The golden rule of liquid supplements is that they should be used in addition to normal meals, and not to replace standard meals.
In contrast to many other medical conditions, people with cystic fibrosis should have a much higher fat intake than normal: fat should supply 35-40% of the daily energy requirement. Lack of the necessary digestive enzymes can cause malabsorption of fat (characterised by an increase in the number of stools that are passed, fatty stools or cramps).
Deficiencies of the essential fatty acids (omega-3 fatty acids such as DHA and EPA, and omega-6) may occur, but if the person receives enzyme replacements, this shouldn't be a problem.
The diet should include sources of essential omega-3 fatty acids, for example salmon, mackerel, herring, tuna, snoek, trout, sardines, pilchards and omega-3-enriched eggs, milk (check long-life milks in your supermarket) and bread.
Serve fish at least three times a week or more, and use omega-3-enriched products. Omega-6 fatty acids are found in most plant oils (sunflower oil). Studies have shown that people with cystic fibrosis benefit from increased intakes of essential fatty acids (EPA and DHA) as these fats help to reduce inflammation.
Cystic fibrosis sufferers may use full-cream milk, cream and full-cream yoghurt to boost both their fat and energy intakes.
Read more: Cystic fibrosis and your diet
Dr Ingrid van Heerden is a registered dietician and holds a doctoral degree in Nutrition and Biochemistry. She believes that "we are what we eat" and offers free nutrition and weight loss advice via her DietDoc service on Health24.com. Read more of her articles.