The Changing CF Diet

Diet remains a very important part of the management of CF. A well-rounded diet including a variety of foods from all food groups is recommended for people living with CF. Good nutrition helps the body fight infections and maintain strength.

Traditionally, CF nutrition focused heavily on a high-calorie, high-fat diet to prevent undernutrition, however, there is no longer a one-size-fits-all CF diet. Nutrition recommendations are becoming increasingly individualised, particularly with the introduction of CFTR modulators. The focus is now on a balanced, nutrient-rich diet that supports gut, bone, heart and metabolic health, while maintaining adequate energy and protein intake.

A Balanced Diet

It is important to follow a balanced diet including all food groups (unless otherwise advised) such as grains and cereals, fruits and vegetables, dairy products and protein foods like meat, chicken, fish, legumes, nuts and eggs.

A balanced diet should focus on:

Fruit and vegetables
Whole grains and legumes
Lean proteins, dairy and alternatives
Being mindful of foods high in sugar and fat

People who have difficulty maintaining their weight may still need additional energy and fat, however the sources of these remain important. Your CF dietitian can help determine what is right for you.

Fibre

Fibre is an important part of a balanced diet for adults with CF and can help support bowel regularity and overall gut health. Good sources of fibre include wholegrain breads and cereals, fruit, vegetables, legumes, nuts and seeds. Adequate fluid intake is also important alongside fibre.

For most adults with CF, fibre recommendations are in line with recommendations for the general Australian population, however for those experiencing constipation, bloating, abdominal pain or other gastrointestinal symptoms, recommendations should be individualised.

Fat

Fat remains an important part of a balanced diet for adults with CF, however, current recommendations have moved away from encouraging a high-fat diet for everyone. The amount of fat needed should be individualised according to nutritional status, energy needs, pancreatic function and CFTR modulator use.

Adults should also focus on eating heart-healthy unsaturated fats, such as olive oil, avocado, nuts, seeds and oily fish, while limiting excessive saturated and trans fats such as fatty and processed meats, pastries, cakes, biscuits and some takeaway foods.

For people who are underweight or have difficulty meeting their energy needs, higher-fat foods may still be useful to increase energy intake and support weight maintenance or gain, but the source of fat remains important.

Protein

Protein is an important dietary component for people with CF, helping to support breathing, strength and recovery from illness. Adults with CF should aim for a palm-sized portion of protein at every meal, alongside protein-rich snacks throughout the day. Choose a variety of protein sources, including lean meat, skinless poultry, fish and eggs, while limiting processed and cured meats. Plant-based and dairy options such as legumes, tofu, nuts, seeds and lower-fat dairy products are also great sources of protein.

For adults with CF who are maintaining a healthy weight, protein intake can generally be guided by general population recommendations, however those who are underweight, losing muscle mass, are unwell or unable to meet their nutritional needs, may require additional protein and energy.

Your CF care team can perform several body composition tests to determine your muscle mass and provide individualised protein recommendations. You can ask about this at clinic.

Carbohydrate

Carbohydrates are an important source of energy and should form part of a balanced diet. Where possible, choose high-fibre, minimally processed carbohydrates such as wholegrain breads and cereals, oats, brown rice, wholemeal pasta, fruit, vegetables and legumes. Many of these carbohydrate sources also contain fibre, which plays an important role in bowel and digestive health, reducing cholesterol and stabilising blood sugars in the general population. See Bowel Health for additional information.

Try to limit carbohydrate sources that are high in added sugar and provide little nutritional value, such as soft drinks, lollies, cakes/biscuits and other highly processed foods. These can cause a rapid rise in blood glucose and, when eaten regularly, can make it harder to maintain stable blood glucose levels.

Calcium

Calcium is important for maintaining strong bones, and adults with CF should generally aim for a higher intake than the general population. Everyday calcium-rich foods include milk, yoghurt, cheese, calcium-fortified soy or other plant milks, tinned salmon or sardines with the bones, calcium-set tofu, almonds, tahini, chia seeds and leafy greens.

Spread calcium intake out across the day rather than just at one meal. Weight bearing and resistance exercise should be used to assist with bone strength alongside calcium intake. Bone health should be reviewed at annual review.

Calcium intake should be reviewed regularly with your CF dietitian, with supplementation considered if your needs cannot be met through food alone.

Water

Staying well hydrated is important for adults with CF. Drinking enough fluid helps keep mucus thinner and easier to clear, supports healthy bowel function and helps replace fluid lost through sweat. Fluid needs may increase during hot weather, exercise, illness or when experiencing increased salt losses.

Water should be the main drink for most people, with individual fluid and salt needs discussed with your CF dietitian or care team.

Navigating Nutritional Changes

Adjusting to changes in appetite and nutritional recommendations can be a significant shift. After years of relying on specific foods to meet energy needs and support health, it’s understandable that a change in recommended food types can be challenging.

Changing Habits

Changing long-held habits will take time. Start small and make it stick:

Change one thing at a time
Make it specific- what, when and how often, rather than “eat better”
Anchor the new habit to something you already do each day
Give it a few weeks to feel automatic before adding the next change
Progress not perfection

Lean on your CF Team

Lean on your CF team for support.

Your dietitian can turn broad advice into one realistic next step
Talk about the barriers- appetite, fatigue, cost, time- not just the goals
Agree how you will check in, so progress gets reviewed and adjusted