CF: General Guidance for Food Intake 2020
Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.
CF: Food and Supplement Intake
For all individuals with cystic fibrosis (CF), it is reasonable for the RDN or international equivalent to advise an age-appropriate, healthy diet that emphasizes culturally appropriate foods associated with positive health outcomes in the general population, including vegetables, fruits, whole grains, seafood, eggs, beans and peas, nuts and seeds, dairy products, and meats and poultry, as tolerated and preferred by the individual with CF, since there is no evidence to suggest that routine modification from a well-balanced, healthy diet is associated with improved outcomes. It is reasonable to advise supplementation with energy, and/or protein-dense foods or oral or enteral supplements, as needed to achieve or maintain normal growth (pediatrics) or BMI status (adults).
CF: Dietary Patterns
For all individuals with cystic fibrosis (CF), it is reasonable for the RDN or international equivalent to consider advising a dietary pattern, individualized for dietary preferences and nutrient needs, that promotes consumption of nutrient-dense foods, including healthy fats and micronutrients.
CF: Meal and Snack Frequency
For all individuals with cystic fibrosis (CF), it is reasonable for the RDN or international equivalent to suggest frequent food intake throughout the day, including at least 3 meals with snacks in between, as needed, in order to meet energy and protein needs and achieve or maintain optimal weight/growth and nutrition status.
Risks/Harms of Implementing This Recommendation
There are no obvious risks or harms associated with these recommendations, but MNT should be individualized to each individual with cystic fibrosis (CF). Foods that are healthy and optimize health are generally easily accessible, but socioeconomic and environmental factors, including food insecurity, should be considered when advising individuals with CF how to improve their dietary intake.
Conditions of Application
Individualize MNT. These recommendations are meant as a general approach for dietary intake for individuals with CF. However, this population is extremely heterogeneous, and MNT should always be tailored to the unique needs of the individual, including preferences and values, nutrition status and supplements, medications, disease exacerbations, co-morbid conditions such as food allergies, CFRD or gastrointestinal symptoms, inflammation, absorption and exocrine pancreatic status and PERT. Individual dietary needs may vary widely depending on pancreatic insufficiency versus insufficiency, response to CFTR modulator therapy, physical activity, and/or other GI related issues.
Potential Costs Associated with Application
There are no obvious costs associated with these recommendations.
Background. Determining which foods should be eaten to maintain nutrition status and address other nutrition-related concerns can be a significant source of stress for individuals with CF and their families. Due to increased energy expenditure and decreased nutrient absorption, particularly of fats and fat-soluble vitamins, the traditional dietary prescription for CF has been a high-energy, high-fat diet (Saxby et al 2017, Turck et al 2016, Stallings et al 2008). In efforts to meet this nutrition prescription, individuals with CF often include energy-dense, nutrient-poor foods in their diets, such as fast food, desserts, packaged snacks, sweetened drinks and fatty meats (Sutherland et al 2019, Calvo-Lerma et al 2019). This may translate to diets that are higher in trans fatty acids and added sugars and lower in fiber in individuals with CF compared to healthy matched controls (Bellissimo et al 2019). While evidence is clear that maintaining adequate nutrition status protects against pulmonary decline (Academy of Nutrition and Dietetics 2019), it is unclear how dietary patterns may differentially modify this relationship. Very few studies have examined if high quantities of energy-dense, nutrient-poor foods may result in increased risk of other co-morbidities, such as further impairment of glucose homeostasis or increased inflammation.
Evidence. The systematic review supporting this guideline examined the relationship between food types, dietary patterns and meal patterns and nutrition-related outcomes (i.e. mortality, pulmonary function, quality of life, anthropometric and relevant lab values, antibiotic use, length of stay, gastrointestinal symptoms) in individuals with CF. However, there were no studies, even observational studies, which examined these nutrition exposures of interest in the pediatric or adult CF populations. Since completing the systematic review, one small cross-sectional study has been published that reported no relationships between intake of whole grains or Healthy Eating Index (HEI)-2015 score and body composition or fasting glucose levels in adults with CF; however, intake of added sugars was positively associated with visceral adipose tissue in individuals with CF (Bellissimo et al 2019). In another small cross-sectional study of adults with CF, dietary glycemic index and glycemic load were significantly positively associated with amount of time spent with blood in the hyperglycemic range, and larger glucose fluctuations, respectively, as determined by continuous blood glucose monitoring (Armaghanian et al 2019). Large, long-term nutrition trials are critically needed in the CF population to determine which dietary patterns are optimal for nutrition-related outcomes, including pulmonary function and glucose homeostasis.
Population Norms in the Absence of Evidence. In the meantime, RDNs and other health professionals must rely on nutrition knowledge as it relates to the general population, according to basic dietetic and nutrition science principles, and adapted to what is known about CF pathology. In the general population, diets rich in energy-dense, nutrient-poor foods have been implicated for several chronic adverse health outcomes including metabolic syndrome (Rodriguez-Monforte et al 2017), inflammation, cardiovascular disease and gut dysbiosis (Casas et al 2018), and a variety of cancers (Grosso et al 2017). Fruit and vegetable consumption, conversely, is associated with reduction in pro-inflammatory mediators and an enhanced immune cell profile (Hosseini et al 2018). Guidance for dietary recommendations for the general population can be found in the Dietary Guideline for Americans and MyPlate (United States Department of Agriculture 2015) or other country-specific guidelines for the general population. Various healthy dietary eating patterns, such as a Mediterranean-style diet, have been proposed and been shown to correlate with positive health outcomes in the general population (United States Department of Agriculture 2015). While a Mediterranean-style diet pattern does not have a strict definition, it generally consists of ample plant foods, olive oil as the primary source of fat, and moderate consumption of fish, poultry and wine (Widmer et al 2015). In the general population, adherence to the Mediterranean Diet was associated with decreased risk of mortality (Soltani et al 2019, Becerra-Tomas et al 2019), CVD (Becerra-Tomas et al 2019, Rosato et al 2019) and CVD risk factors (Rees et al 2019) and glycemic control (Esposito et al 2015).
One of the greatest challenges in nutrition care for individuals with CF will be to encourage a diet that is not only energy-dense, as needed, but is also nutrient-dense and relies on food-based nutrition when possible, since nutrients in isolation may not have the same health benefits (ex: antioxidant supplementation trials in CF have provided mixed results; although the majority have used small sample sizes (Ciofu et al 2014, Sagel et al 2011, Sagel et al 2018, Shamseer et al 2010)). However, individuals with CF and exocrine pancreatic insufficiency have higher fat-soluble vitamin needs due to malabsorption, and it is not realistic to expect that all needs can be met by diet alone. Supplementation with fat-soluble vitamins is standard practice for individuals with CF. Guidance for supplementation of micronutrients and macronutrients (oral or enteral nutrition supplementation) are outside of the scope of this guideline but are addressed in other nutrition guidelines for individuals with CF (Recommendations Overview Table).
Recommendation Strength Rationale
These recommendations are based on expert consensus/opinion since there was no evidence included in the systematic review that examined the relationships between intake of foods or food groups, dietary patterns or meal patterns on nutrition-related outcomes.
- Risks/Harms of Implementing This Recommendation
The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).
References not graded in Academy of Nutrition and Dietetics Evidence Analysis Process
- Academy of Nutrition and Dietetics Evidence Analaysis Lirbary. "In individuals with CF, what is the longitudinal relationship (at least 3 months) between weight and growth parameters and FEV1?". Evidence Analysis Library Cystic Fibrosis Systematic Review web site. https://www.andeal.org/topic.cfm?menu=5876&cat=5979. Updated August 2019. Accessed September 10, 2019.
- Armaghanian N, Atkinson F, Taylor N, et al. Dietary intake in cystic fibrosis and its role in glucose metabolism. Clin Nutr. 2019.
- Becerra-Tomas N, Blanco Mejia S, Viguiliouk E, et al. Mediterranean diet, cardiovascular disease and mortality in diabetes: A systematic review and meta-analysis of prospective cohort studies and randomized clinical trials. Crit Rev Food Sci Nutr. 2019:1-21.
- Bellissimo MP, Zhang I, Ivie EA, et al. Visceral adipose tissue is associated with poor diet quality and higher fasting glucose in adults with cystic fibrosis. J Cyst Fibros. 2019;18(3):430-435.
- Calvo-Lerma J, Hulst J, Boon M, et al. The relative contribution of food groups to macronutrient intake in children with cystic fibrosis: a european multicenter assessment. J Acad Nutr Diet. 2019;119(8):1305-1319.
- Casas R, Castro-Barquero S, Estruch R, Sacanella E. Nutrition and cardiovascular health. Int J Mol Sci. 2018;19(12).
- Ciofu O, Lykkesfeldt J. Antioxidant supplementation for lung disease in cystic fibrosis. Cochrane Database Syst Rev. 2014:(8)-2014 Aug 2007.
- Esposito K, Maiorino MI, Bellastella G, Chiodini P, Panagiotakos D, Giugliano D. A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses. BMJ Open. 2015;5(8):e008222.
- Grosso G, Bella F, Godos J, et al. Possible role of diet in cancer: systematic review and multiple meta-analyses of dietary patterns, lifestyle factors, and cancer risk. Nutr Rev. 2017;75(6):405-419.
- Hosseini B, Berthon BS, Saedisomeolia A, et al. Effects of fruit and vegetable consumption on inflammatory biomarkers and immune cell populations: a systematic literature review and meta-analysis. Am J Clin Nutr. 2018;108(1):136-155.
- Rees K, Takeda A, Martin N, et al. Mediterranean-style diet for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2019;3:Cd009825.
- Rodriguez-Monforte M, Sanchez E, Barrio F, Costa B, Flores-Mateo G. Metabolic syndrome and dietary patterns: a systematic review and meta-analysis of observational studies. Eur J Nutr. 2017;56(3):925-947.
- Rosato V, Temple NJ, La Vecchia C, Castellan G, Tavani A, Guercio V. Mediterranean diet and cardiovascular disease: a systematic review and meta-analysis of observational studies. Eur J Nutr. 2019;58(1):173-191.
- Sagel SD, Khan U, Jain R, et al. Effects of an antioxidant-enriched multivitamin in cystic fibrosis: randomized, controlled, multicenter trial. Am J Respir Crit Care Med. 2018(9421642).
- Sagel SD, Sontag MK, Anthony MM, Emmett P, Papas KA. Effect of an antioxidant-rich multivitamin supplement in cystic fibrosis. J Cystic Fibros. 2011;10(1):31-36.
- Saxby N. PC, Kench A., King S., Crowder T., van der Haak N. and the Australian and New Zealand Cystic Fibrosis Nutrition Guideline Authorship Group. Nutrition Guidelines for Cystic Fibrosis in Australia and New Zealand. In. Sydney: Thoracic Society of Australia and New Zealand; 2017.
- Shamseer L, Adams D, Brown N, Johnson JA, Vohra S. Antioxidant micronutrients for lung disease in cystic fibrosis. Cochrane Database Syst Rev. 2010(12):CD007020.
- Soltani S, Jayedi A, Shab-Bidar S, Becerra-Tomas N, Salas-Salvado J. Adherence to the Mediterranean diet in relation to all-cause mortality: a systematic review and dose-response meta-analysis of prospective cohort studies. Adv Nutr. 2019.
- Stallings VA, Stark LJ, Robinson KA, et al. Evidence-based practice recommendations for nutrition-related management of children and adults with cystic fibrosis and pancreatic insufficiency: results of a systematic review. J Am Diet Assoc. 2008;108(5):832-839.
- Sutherland R, Katz T, Liu V, et al. Dietary intake of energy-dense, nutrient-poor and nutrient-dense food sources in children with cystic fibrosis. J Cyst Fibros. 2018;17(6):804-810.
- Turck D, Braegger CP, Colombo C, et al. ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with cystic fibrosis. Clin Nutrition (Edinburgh, Scotland). 2016;35(3):557-577.
- United States Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans.2015.
- Widmer RJ, Flammer AJ, Lerman LO, Lerman A. The Mediterranean diet, its components, and cardiovascular disease. Am J Med. 2015;128(3):229-238.