Recruiting

FEED-CF

Sponsor:

Emory University

Code:

NCT05766774

Conditions

Cystic Fibrosis

Cystic Fibrosis-related Diabetes

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Low-added sugar, high-fat diet

High-added sugar, high-fat CF diet

Study Details

Brief summary:

The goal of this study is to determine the extent to which excess dietary sugars serve as a precipitating factor in glucose intolerance in adults with cystic fibrosis (CF), a population at especially high risk for a unique form of diabetes (CF-related diabetes, CFRD) and with standard-of-care dietary recommendations (high-calorie, high-fat) that conflict with recommendations for other forms of diabetes.

This trial will investigate if the typical high-sugar, high-fat CF diet plays a role in diabetes risk and visceral fat accumulation in people with CF. A total of 30 participants will get a low-added sugar, high-fat diet and the other 30 will get a standard CF diet with no sugar restrictions. Participants will be randomized to the diet group they are assigned. All foods will be provided for 8 weeks.

Conditions

Cystic Fibrosis

Cystic Fibrosis-related Diabetes

Study ID

NCT05766774

Start date

Jun 28, 2023

Status verified date

Jun, 2026

Completion date

Jun 30, 2028

Anticipated

Primary completion date

Jun 30, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Confirmed CF diagnosis
2. Ages 18 years and older
3. Baseline estimated daily total added sugar intake >16 tsp, as estimated from the Dietary Screener Questionnaire (DSQ).

Exclusion Criteria:

1. Nocturnal tube feeds
2. BMI <18.5 kg/m2
3. Life expectancy < 12 months
4. Confirmed diagnosis of CFRD
5. Screening OGTT showing fasting hyperglycemia (≥126 mg/dL)
6. Chronic steroid use
7. Current pregnancy or lactation
8. Inability/unwillingness to consume the majority of foods on the menu during the study period
9. MRI-incompatible metal that cannot be removed for testing
10. Uncontrolled exocrine pancreatic insufficiency/malabsorption
11. Clinically instability, defined as no changes in medical regimen (including medications and pulmonary exacerbations) for at least 21 days prior to study visit
12. Initiation of CFTR modulator within previous 8 weeks OR unstable changes in weight and lung function due to CFTR modulator use
13. Actively trying to gain or lose weight
14. Any food allergies or intolerances that cannot be accommodated
15. Any medical condition deemed by the a study physician or PI that may preclude completion of the study or interfere with primary end points.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Low-added sugar, high-fat diet Arm

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.

active comparator: Typical CF diet Arm

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.

Interventions

Low-added sugar, high-fat diet

Consist of <5% kcal from added sugars as recommended by the American Heart Association, and the glycemic index will be 45 or lower (25% lower than typical CF diet). The macronutrient composition of both study diets will reflect the general CF recommendations for macronutrients: 35-40% of total kcal from fat and 15-20% total kcal from protein.

High-added sugar, high-fat CF diet

Consist of ≥13% kcal from added sugars and the glycemic index will be >60. The macronutrient composition of both study diets will reflect the general CF recommendations for macronutrients: 35-40% of total kcal from fat and 15-20% total kcal from protein.

Primary outcome measure

  • Change in acute insulin response to arginine (AIRarg) from baseline [ Time Frame: Baseline and 8 weeks post intervention ]
  • Change in acute C-peptide (ACRarg) from baseline [ Time Frame: Baseline and 8 weeks post intervention ]
  • Change in visceral adipose tissue from baseline [ Time Frame: Baseline and 8 weeks post intervention ]
  • Change in fasted plasma Eh[CySS] from baseline [ Time Frame: Baseline and 8 weeks post intervention ]

Central Contacts and Locations

Central contacts

Jessica A Alvarez, PhD, RD

404-727-1390jessica.alvarez@emory.edu

Swati Zaveri, PhD

440-778-8373swati.shital.zaveri@emory.edu

Locations

Emory University Hospital

Recruiting

Atlanta, Georgia, United States, 30322

Contacts

Swati Zaveri, PhD

440-778-8373swati.shital.zaveri@emory.edu

More Information

Sponsor

Emory University

Last update posted

Jun 3, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-15. This information was provided to ClinicalTrials.gov by Emory University on 2026-06-03. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.