Low-Sugar High-Fat Diet for Cystic Fibrosis

(FEED-CF Trial)

Overseen By Swati Zaveri, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Emory University

Must not be taking: Steroids

Disqualifiers: CFRD, Pregnancy, Lactation, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 7

Duration: 8 weeks

60 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether a diet low in added sugars but high in fat can reduce diabetes risk in people with cystic fibrosis (CF). Participants will follow either a typical high-sugar, high-fat CF diet (the "High-added sugar, high-fat CF diet") or a low-sugar, high-fat diet (the "Low-added sugar, high-fat diet") for eight weeks. Researchers aim to determine if reducing sugar intake helps prevent diabetes and decreases fat around the organs. Individuals with CF who consume more than 16 teaspoons of added sugar daily and manage their condition without certain complications may be suitable candidates. As an unphased trial, this study offers a unique opportunity to contribute to groundbreaking research that could improve dietary recommendations for CF patients.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it does require that your medical regimen, including medications, has not changed for at least 21 days before the study. This suggests that you should not make changes to your medications right before or during the trial.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that a diet low in added sugar and high in fat is safe for people with cystic fibrosis (CF). An earlier study found that adults with CF tolerated this diet well, with no major safety issues or serious side effects. This finding provides a solid basis for further research.

The aim is to determine if reducing sugar can help address issues like glucose intolerance and body fat in people with CF. Participants on this diet avoided common problems linked to high sugar intake, suggesting it might be a good option for those concerned about the risk of diabetes. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the new dietary approaches for cystic fibrosis (CF) because they explore how altering sugar intake can impact health. Unlike the typical CF diet, which is high in added sugars and fats, the low-added sugar, high-fat diet aims to manage energy intake while potentially reducing the negative effects associated with high sugar consumption. This unique approach could offer insights into how diet modification might improve the quality of life and health outcomes for people with CF. By delivering all meals directly to participants' homes, the study ensures precise control over dietary intake, which is crucial for understanding the true effects of these dietary changes.

What evidence suggests that this trial's diets could be effective for cystic fibrosis-related diabetes?

Research has shown that reducing added sugar in the diet may help people with cystic fibrosis (CF) manage blood sugar issues. One study found that consuming less added sugar improved diabetes risk markers and reduced belly fat. These changes are crucial for people with CF, who are more prone to developing CF-related diabetes (CFRD). Another study indicated that the typical high-fat, high-sugar diet for CF could harm heart health as individuals with CF age. This trial will compare a low-added sugar, high-fat diet with a typical high-added sugar, high-fat CF diet. Reducing added sugar while maintaining a high-fat diet might improve health for those with CF. ^{1 2 3 6 7}

Who Is on the Research Team?

Jessica A Alvarez, PhD, RD

Principal Investigator

Emory University

Are You a Good Fit for This Trial?

Adults over 18 with confirmed cystic fibrosis, who consume more than 16 teaspoons of added sugar daily and have exocrine pancreatic insufficiency can join. Those with CFRD, recent CFTR modulator use, organ transplant waiting list status, life expectancy under a year, uncontrolled conditions or dietary restrictions that conflict with the study's menu are excluded.

Inclusion Criteria

Your daily added sugar intake is more than 16 teaspoons, as calculated from a questionnaire or food record.

I have been diagnosed with cystic fibrosis based on sweat test or genetic testing.

My pancreas does not produce enough digestive enzymes.

Exclusion Criteria

Current pregnancy or lactation or plans to become pregnant during study period

Any food allergies or intolerances that cannot be accommodated

My fasting blood sugar level is 126 mg/dL or higher.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1 visit

1 visit (in-person)

Baseline

Baseline visit for an insulin secretion test and MRI testing to measure visceral fat

1 visit

1 visit (in-person)

Treatment

Participants receive either a low-added sugar, high-fat diet or a typical CF diet for 8 weeks

8 weeks

Food delivered every 3-4 days

Midpoint Check-in

4-week visit for an oral glucose tolerance test and in-person check-in

1 visit

1 visit (in-person)

Follow-up

8-week visit for another GPA and MRI to assess changes in risk markers for diabetes and visceral fat

1 visit

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• High-added sugar, high-fat CF diet
• Low-added sugar, high-fat diet

Trial Overview The FEED-CF trial is testing how diet affects diabetes risk in cystic fibrosis patients by comparing two diets: one low in added sugars but high in fats versus the standard high-sugar, high-fat CF diet. Participants will be randomly assigned to one of these diets for 8 weeks.

How Is the Trial Designed?

Group I: Low-added sugar, high-fat diet Arm Experimental Treatment 1 Intervention

Patients will receive a low-added sugar, high-fat diet for 8 weeks. Study menus will be designed by registered dietitians using the Nutrient Database System for Research (NDSR) software program with a 2-wk rotation.Total kcal provided will be individually tailored to maintain body weight and adjusted throughout as needed. All foods (including snacks and drinks) for 8 wks will be delivered to participants' homes. Menus will be designed so that food will be delivered to subjects' homes every 3-4 days. It will be expected that participants consume only the foods provided by the study.

Group II: Typical CF diet Arm Active Control 1 Intervention

Patients will receive a high-added sugar, high-fat CF diet for 8 weeks. Study menus will be designed by registered dietitians using the Nutrient Database System for Research (NDSR) software program with a 2-wk rotation. Total kcal provided will be individually tailored to maintain body weight and adjusted throughout as needed. All foods (including snacks and drinks) for 8 wks will be delivered to participants' homes. Menus will be designed so that food will be delivered to subjects' homes every 3-4 days. It will be expected that participants consume only the foods provided by the study.

Who Is Running the Clinical Trial?

Emory University

Lead Sponsor

Trials

1,735

Recruited

2,605,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

In a study of 2,197 adults, there was little evidence that consuming sugary fatty foods is linked to obesity, as the average intake of these foods was only about 12% to 15% of total energy intake.

Interestingly, the study found a weak negative correlation between sugar intake and BMI, suggesting that lower sugar consumption did not necessarily lead to lower body weight, especially in men.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Are high-fat, high-sugar foods and diets conducive to obesity? Gibson, SA.[2019]

In a study involving 20 participants (10 normal weight and 10 obese), consuming HFCS-sweetened beverages for 2 weeks did not significantly affect body weight, insulin sensitivity, or other metabolic responses in either group.

Obese individuals exhibited lower physical activity levels and poorer metabolic profiles compared to normal weight individuals, but the short-term effects of HFCS consumption were similar regardless of weight classification.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Weight classification does not influence the short-term endocrine or metabolic effects of high-fructose corn syrup-sweetened beverages. Heden, TD., Liu, Y., Kearney, ML., et al.[2014]

Intake of saturated trans fatty acids and refined carbohydrates, especially sugar, is linked to higher risks of obesity, diabetes, and cardiovascular disease (CVD), highlighting the importance of dietary guidelines that limit these components.

A recent randomized controlled trial demonstrated that adhering to current dietary guidelines can positively impact cardiovascular risk and nutrient intake compared to a traditional UK diet, supporting the need for balanced macronutrient consumption.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

How important is the relative balance of fat and carbohydrate as sources of energy in relation to health? Sanders, TA.[2022]

In a study of 613 Canadian children aged 8-10, higher intake of added sugars, particularly from liquid sources, was linked to poorer diet quality, characterized by lower consumption of fruits, vegetables, and essential micronutrients.

Liquid added sugars were specifically associated with increased adiposity indicators, such as higher BMI and waist circumference, suggesting that reducing liquid sugar intake may be important for managing weight in children.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Associations between added sugar (solid vs. liquid) intakes, diet quality, and adiposity indicators in Canadian children. Wang, J., Shang, L., Light, K., et al.[2016]

In a study involving six healthy men, energy intake did not significantly increase with high-fat diets when compared to low-fat and medium-fat diets that had the same energy density, suggesting that fat does not inherently lead to higher energy consumption.

The findings indicate that neither carbohydrate nor fat intake is strictly regulated by the body's energy intake models, challenging the glucostatic and glycogenostatic theories of how we regulate food intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Covert manipulation of the dietary fat to carbohydrate ratio of isoenergetically dense diets: effect on food intake in feeding men ad libitum. Stubbs, RJ., Harbron, CG., Prentice, AM.[2014]

Diets high in fat are more likely to lead to body fat accumulation compared to diets high in carbohydrates, indicating that fat intake is a significant contributor to obesity.

Current evidence suggests that high sugar intake does not correlate with obesity, as it is negatively associated with obesity indexes, contrasting with the positive association found with high-fat diets.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sugar and body weight regulation. Hill, JO., Prentice, AM.[2018]

In a study of 169 participants on a hypocaloric, low-fat diet, significant reductions in high-fat and high-added-sugar food groups were observed over 6 months, indicating effective dietary changes.

Specifically, decreases in the intake of high-fat meats were significantly associated with reductions in overall energy intake, fat intake percentage, and weight loss, suggesting that targeting these foods may enhance weight loss outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Decreases in High-Fat and/or High-Added-Sugar Food Group Intake Occur when a Hypocaloric, Low-Fat Diet Is Prescribed Within a Lifestyle Intervention: A Secondary Cohort Analysis. Sheikh, VK., Raynor, HA.[2021]

Diet plays a crucial role in cardiovascular disease risk, with high fat consumption linked to increased serum cholesterol levels; however, a study in Belgium found that dietary changes led to only a 3.5% reduction in cholesterol levels, highlighting the challenges in achieving significant dietary impact through physician guidance.

Current research suggests that a modified fat diet, which is rich in mono-unsaturated fatty acids, may be more effective than a low fat diet, especially for diabetic patients, as it offers practical benefits for reducing saturated fat intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical approaches to healthier diet modifications. Muls, E., Vansant, G.[2017]

A modified fat diet enriched with monounsaturated fats (MUFA) can effectively support weight loss through calorie counting or ad libitum intake, provided that high MUFA foods contribute no more than 20% of total energy.

This diet not only aids in weight loss but also offers health benefits such as improved metabolic control in Type 2 diabetes and reduced cardiovascular disease risk, thanks to its rich content of MUFA, antioxidants, and bio-active phytochemicals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Is a low fat diet the optimal way to cut energy intake over the long-term in overweight people? Walker, KZ., O'Dea, K.[2006]

In a study of 288 children, higher consumption of commercial complementary food (CF) in infancy was linked to increased added sugar intake both in infancy and later during pre-school and primary-school years.

The findings suggest that introducing home-made CF or selecting commercial CF without added sugar could help reduce overall sugar intake in young children, potentially preventing a preference for sweet tastes later in life.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Commercial complementary food consumption is prospectively associated with added sugar intake in childhood. Foterek, K., Buyken, AE., Bolzenius, K., et al.[2018]

Fructose consumption increases the enzyme ketohexokinase-C (KHK-C), which enhances lipogenesis and reduces fatty acid oxidation, contributing to metabolic dysfunction in mice fed a high-fat diet.

The study reveals that KHK-C modifies global protein acetylation, including the acetylation of CPT1α, leading to decreased levels of this protein and increased triglyceride accumulation, highlighting a novel mechanism by which dietary fructose exacerbates the effects of a high-fat diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ketohexokinase-C regulates global protein acetylation to decrease carnitine palmitoyltransferase 1a-mediated fatty acid oxidation. Helsley, RN., Park, SH., Vekaria, HJ., et al.[2023]

In a study of 1719 French adults, those with excessive free sugar (FS) intake (41% of the population) had lower nutritional quality diets and higher overall energy consumption compared to those with acceptable FS levels.

To improve nutritional adequacy, both groups needed to increase their intake of fresh fruits, starchy foods, and plain yogurts, while those with excessive FS intake specifically benefited from reducing sugar-sweetened beverages and sweet products.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Individual Diet Modeling Shows How to Balance the Diet of French Adults with or without Excessive Free Sugar Intakes. Lluch, A., Maillot, M., Gazan, R., et al.[2023]

Recent reviews of randomized controlled trials and cohort studies suggest that normal levels of added sugars in the human diet do not uniquely increase the risk of obesity, diabetes, or cardiovascular disease.

The findings indicate that common added sugars, like sucrose and high-fructose corn syrup, when consumed within typical dietary limits, do not pose additional health risks compared to other carbohydrates.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Added sugars and risk factors for obesity, diabetes and heart disease. Rippe, JM., Angelopoulos, TJ.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11683900/

Low-added sugar dietary intervention study to mitigate ... Low-added sugar dietary intervention study to mitigate glucose intolerance and improve body composition in adults with cystic fibrosis

2. clinicaltrials.gov clinicaltrials.gov/study/NCT05766774?term=NIDDK%20endocrine%20and%20diabetes&spons=NIDDK&aggFilters=status:not%20rec%20act&viewType=Table&rank=5

NCT05766774 | FEED-Cystic Fibrosis (FEED-CF) In this study, the investigators will test if a low-added sugar diet improves risk markers for diabetes and decreases visceral fat over 8 weeks. The study will ...

3. withpower.com withpower.com/trial/phase-cystic-fibrosis-2-2023-ed0c5

Low-Sugar High-Fat Diet for Cystic Fibrosis (FEED-CF Trial) In a study of 169 participants on a hypocaloric, low-fat diet, significant reductions in high-fat and high-added-sugar food groups were observed over 6 months, ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10745571/

Dietary Intake & Faecal Microbiota in Cystic Fibrosis Children The results reveal that a “high-fat, high-energy” diet does not satisfy dietary fibre intake from healthy food sources in children with CF.

5. sciencedirect.com sciencedirect.com/science/article/pii/S1569199323001406

Nutritional considerations for a new era: CF foundation paper The traditional high fat, high calorie CF diet may have negative nutritional and cardiovascular consequences as pwCF age.

6. sciencedirect.com sciencedirect.com/science/article/pii/S1569199323008743

What do people with cystic fibrosis eat? Diet quality, ... The overall diet quality of adults with cystic fibrosis is poor. All studies were over cystic fibrosis recommended total energy intake from fat.

7. frontiersin.org frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1441201/full

Safety and tolerability of a low glycemic load dietary ... Discussion: A LGL dietary intervention was safe and well tolerated in adults with CF and AGT. These results lay the groundwork for future trials ...