Cystic FibrosisFEED-CFNCT05766774
FEED-Cystic Fibrosis (FEED-CF)
A study testing Low-added sugar, high-fat diet and High-added sugar, high-fat CF diet in people with Cystic Fibrosis and Cystic Fibrosis-related Diabetes, run by Emory University at 1 site in United States.
Trial 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… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cystic Fibrosis, Cystic Fibrosis-related Diabetes
- What is being tested?
- Low-added sugar, high-fat diet and High-added sugar, high-fat CF diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Jun 2023to 30 Jun 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Confirmed CF diagnosis
- Ages 18 years and older
- Baseline estimated daily total added sugar intake >16 tsp, as estimated from the Dietary Screener Questionnaire (DSQ).
Who cannot join
- Nocturnal tube feeds
- BMI <18.5 kg/m2
- Life expectancy < 12 months
- Confirmed diagnosis of CFRD
- Screening OGTT showing fasting hyperglycemia (≥126 mg/dL)
- Chronic steroid use
Show all 15Show fewer
- Current pregnancy or lactation
- Inability/unwillingness to consume the majority of foods on the menu during the study period
- MRI-incompatible metal that cannot be removed for testing
- Uncontrolled exocrine pancreatic insufficiency/malabsorption
- Clinically instability, defined as no changes in medical regimen (including medications and pulmonary exacerbations) for at least 21 days prior to study visit
- Initiation of CFTR modulator within previous 8 weeks OR unstable changes in weight and lung function due to CFTR modulator use
- Actively trying to gain or lose weight
- Any food allergies or intolerances that cannot be accommodated
- Any medical condition deemed by the a study physician or PI that may preclude completion of the study or interfere with primary end points.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Emory University Hospital
Atlanta, Georgia, 30322
Swati Zaveri, PhD, 440-778-8373, swati.shital.zaveri@emory.edu
About this study
Official title: Feeding Study to Optimize Endocrine Dysfunction in Cystic Fibrosis
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.
Read the detailed description
Approximately half of adults with cystic fibrosis (CF), a genetic disease, will develop diabetes. Dietary strategies shown to be successful in preventing or treating other forms of diabetes in people without CF contradict current nutritional recommendations for people with CF. The nutrition standard-of-care in CF is prescription of an unrestricted high-calorie, high-fat diet because of malnutrition. However, the standard CF diet translates to low-quality diets, with excess added sugars well-above general population recommendations. Also the investigators have shown that people with CF have more fat around their abdominal organs (called visceral fat) compared to healthy controls. The hypothesis is that the typical high-sugar, high-fat CF diet plays a role in diabetes risk and visceral fat accumulation in people with 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 recruit 60 participants 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. There will be a total of 4 study visits at the Emory Hospital clinical research unit. These will include: 1) a screening visit with an oral glucose tolerance test with blood draws to determine if they already have diabetes, 2) a baseline visit for an insulin secretion test (called glucose-potentiated arginine (GPA) stimulation test) to assess risk for diabetes, as well as magnetic resonance imaging (MRI) testing to measure visceral fat, 3) a 4-week visit for another oral glucose tolerance test and in-person check-in, and 4) an 8-week visit for another GPA and MRI. Blood samples will be collected and banked. In addition to all meals provided for 8 weeks, participants will be compensated for their time and effort. Participants will be recruited from patients seen at the Emory CF Clinic. Informed consent will be performed prior to any study testing. The investigators hope this study will contribute to the development of new standardized nutrition guidelines for people living with CF.
- Conditions
- Cystic Fibrosis, Cystic Fibrosis-related Diabetes
- Being tested
- Low-added sugar, high-fat diet, High-added sugar, high-fat CF diet
- Medical subject headings
- Cystic Fibrosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low-added sugar, high-fat dietOther
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 dietOther
Also called Typical 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.
| Study group | Role | What they receive |
|---|---|---|
| Low-added sugar, high-fat diet Arm | Experimental | 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. Receives: Other: Low-added sugar, high-fat diet |
| Typical CF diet Arm | Active comparator | 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. Receives: Other: High-added sugar, high-fat CF diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in acute insulin response to arginine (AIRarg) from baseline
Participants will undergo a Glucose-Potentiated Arginine Stimulation (GPA) Test after a 10-12 hour overnight fast to measure acute insulin (AIRarg) responses during a 230 and 340 mg/dl glucose clamp. This test will measure changes in beta cell secretory capacity.
Measured: Baseline and 8 weeks post intervention
Change in acute C-peptide (ACRarg) from baseline
Participants will undergo a Glucose-Potentiated Arginine Stimulation (GPA) Test after a 10-12 hour overnight fast to measure acute C-peptide (ACRarg) responses during a 230 and 340 mg/dl glucose clamp. This test will measure changes in beta cell secretory capacity.
Measured: Baseline and 8 weeks post intervention
Change in visceral adipose tissue from baseline
Dual energy X-ray absorptiometry (DEXA)-derived measurement of visceral adipose tissue (VAT) will be assessed with a GE Lunar iDXA machine. This will enable assessment of changes in body composition over the study.
Measured: Baseline and 8 weeks post intervention
Change in fasted plasma Eh[CySS] from baseline
Change in plasma Cysteine/Cystine Redox Potential (Eh[CySS]) will be measured.
Measured: Baseline and 8 weeks post intervention
Secondary outcomes (3)
Change in Gastrointestinal Symptom Rating Scale (GSRS) scale
The GSRS is a 15 items combine into five symptom clusters: Reflux, Abdominal pain, Indigestion, Diarrhea and Constipation.
Possible score range is 0-7, with 7 being the worst and 0 being the best (no symptoms).
Measured: Baseline and 8 weeks post intervention
Change in hepatic and pancreatic fat volume
Dual energy X-ray absorptiometry (DEXA)-derived measurement of visceral adipose tissue (VAT) for hepatic and pancreatic fat volume. Will be assessed with a GE Lunar iDXA machine.
Measured: Baseline and 8 weeks post intervention
Change in fasted plasma Eh[GSSG]
Change in plasma glutathione disulfide (GSSG) (Eh[CySS]) will be measured.
Measured: Baseline and 8 weeks post intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2023
- Study start28 Jun 2023
- Primary completion30 Jun 2028 (estimated)
- Study completion30 Jun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Cystic FibrosisStudies of the same condition, open and under way.
- More trials run by Emory UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A double-blind, randomized, parallel-group design clinical trial.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Emory University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jessica Alvarez, Emory University
- Investigators
- Jessica A Alvarez, PhD, RD, Principal investigator, Emory University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05766774
- Sponsor's protocol ID
- STUDY00004517
- Other IDs
- 1R01DK133523-01, 2025P010830
- Acronym
- FEED-CF
- Status last verified
- Jun 2026
- First submitted
- 21 Feb 2023
- Last updated
- 3 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Actual clinical study data in raw and summary form, with protected health information removed, as well as access to the study database, will be available for reference of qualified professional colleagues and auditors up to 10 years after study publication. With appropriate subject informed consent, clinical and research data obtained from this study will be deposited into the Georgia CF Data Warehouse of the NDDK P30-supported Georgia Cystic Fibrosis Clinical and Translational Core Center.
Publications
Zaveri S, Stecenko A, Hunt WR, Goss A, Sharma P, Hartman TJ, Easley K, Chandler JD, Burley TM, Driggers C, Ciccarella A, Zhou H, Narlow K, Ziegler TR, Daley T, Vellanki P, Alvarez J. Low-added sugar dietary intervention study to mitigate glucose intolerance and improve body composition in adults with cystic fibrosis: a protocol of a double-blind, randomised study. BMJ Open. 2024 Dec 26;14(12):e092503. doi: 10.1136/bmjopen-2024-092503.
PubMed 39725418
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Feeding Study to Optimize Endocrine Dysfunction in Cystic Fibrosis
- ClinicalTrials.gov ID
- NCT05766774
- Acronym / sponsor ID
- FEED-CF / STUDY00004517
- Conditions
- Cystic Fibrosis, Cystic Fibrosis-related Diabetes
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Emory UniversityUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 28 Jun 2023 (actual)
- Primary completion
- 30 Jun 2028 (estimated)
- Study completion
- 30 Jun 2028 (estimated)
- First posted
- 13 Mar 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Approximately half of adults with cystic fibrosis (CF), a genetic disease, will develop diabetes. Dietary strategies shown to be successful in preventing or treating other forms of diabetes in people without CF contradict current nutritional recommendations for people with CF. The nutrition standard-of-care in CF is prescription of an unrestricted high-calorie, high-fat diet because of malnutrition. However, the standard CF diet translates to low-quality diets, with excess added sugars well-above general population recommendations. Also the investigators have shown that people with CF have more fat around their abdominal organs (called visceral fat) compared to healthy controls. The hypothesis is that the typical high-sugar, high-fat CF diet plays a role in diabetes risk and visceral fat accumulation in people with 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 recruit 60 participants 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. There will be a total of 4 study visits at the Emory Hospital clinical research unit. These will include: 1) a screening visit with an oral glucose tolerance test with blood draws to determine if they already have diabetes, 2) a baseline visit for an insulin secretion test (called glucose-potentiated arginine (GPA) stimulation test) to assess risk for diabetes, as well as magnetic resonance imaging (MRI) testing to measure visceral fat, 3) a 4-week visit for another oral glucose tolerance test and in-person check-in, and 4) an 8-week visit for another GPA and MRI. Blood samples will be collected and banked. In addition to all meals provided for 8 weeks, participants will be compensated for their time and effort. Participants will be recruited from patients seen at the Emory CF Clinic. Informed consent will be performed prior to any study testing. The investigators hope this study will contribute to the development of new standardized nutrition guidelines for people living with CF.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- A double-blind, randomized, parallel-group design clinical trial.
| Arm | Type | Receives |
|---|---|---|
| Low-added sugar, high-fat diet Arm | Experimental | Other: Low-added sugar, high-fat dietPatients 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. |
| Typical CF diet Arm | Active comparator | Other: High-added sugar, high-fat CF dietPatients 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 may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Confirmed CF diagnosis
- Ages 18 years and older
- Baseline estimated daily total added sugar intake >16 tsp, as estimated from the Dietary Screener Questionnaire (DSQ).
Key exclusion criteria (15 listed)
- Nocturnal tube feeds
- BMI <18.5 kg/m2
- Life expectancy < 12 months
- Confirmed diagnosis of CFRD
- Screening OGTT showing fasting hyperglycemia (≥126 mg/dL)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Low-added sugar, high-fat dietConsist 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. | Other | Low-added sugar, high-fat diet Arm |
| High-added sugar, high-fat CF dietAlso: Typical CF dietConsist 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. | Other | Typical CF diet Arm |
Primary outcome
Change in acute insulin response to arginine (AIRarg) from baseline
Time frame: Baseline and 8 weeks post intervention
Participants will undergo a Glucose-Potentiated Arginine Stimulation (GPA) Test after a 10-12 hour overnight fast to measure acute insulin (AIRarg) responses during a 230 and 340 mg/dl glucose clamp. This test will measure changes in beta cell secretory capacity.
Change in acute C-peptide (ACRarg) from baseline
Time frame: Baseline and 8 weeks post intervention
Participants will undergo a Glucose-Potentiated Arginine Stimulation (GPA) Test after a 10-12 hour overnight fast to measure acute C-peptide (ACRarg) responses during a 230 and 340 mg/dl glucose clamp. This test will measure changes in beta cell secretory capacity.
Change in visceral adipose tissue from baseline
Time frame: Baseline and 8 weeks post intervention
Dual energy X-ray absorptiometry (DEXA)-derived measurement of visceral adipose tissue (VAT) will be assessed with a GE Lunar iDXA machine. This will enable assessment of changes in body composition over the study.
Change in fasted plasma Eh[CySS] from baseline
Time frame: Baseline and 8 weeks post intervention
Change in plasma Cysteine/Cystine Redox Potential (Eh[CySS]) will be measured.
3 secondary outcomes
Change in Gastrointestinal Symptom Rating Scale (GSRS) scale
Time frame: Baseline and 8 weeks post intervention
Change in hepatic and pancreatic fat volume
Time frame: Baseline and 8 weeks post intervention
Change in fasted plasma Eh[GSSG]
Time frame: Baseline and 8 weeks post intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jun 2026.
- Derived from this study: PubMed 39725418Zaveri S, Stecenko A, Hunt WR, Goss A, Sharma P, Hartman TJ, Easley K, Chandler JD, Burley TM, Driggers C, Ciccarella A, Zhou H, Narlow K, Ziegler TR, Daley T, Vellanki P, Alvarez J. Low-added sugar dietary intervention study to mitigate glucose intolerance and improve body composition in adults with cystic fibrosis: a protocol of a double-blind, randomised study. BMJ Open. 2024 Dec 26;14(12):e092503. doi: 10.1136/bmjopen-2024-092503.
- Individual participant dataSharing planned: Yes. Actual clinical study data in raw and summary form, with protected health information removed, as well as access to the study database, will be available for reference of qualified professional colleagues and auditors up to 10 years after study publication. With appropriate subject informed consent, clinical and research data obtained from this study will be deposited into the Georgia CF Data Warehouse of the NDDK P30-supported Georgia Cystic Fibrosis Clinical and Translational Core Center.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jessica A Alvarez, PhD, RD principal investigator
Emory University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low-added sugar, high-fat diet and High-added sugar, high-fat CF diet in people with Cystic Fibrosis and Cystic Fibrosis-related Diabetes, run by Emory University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jessica A Alvarez, PhD, RD (404-727-1390, jessica.alvarez@emory.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in acute insulin response to arginine (AIRarg) from baseline (time frame: Baseline and 8 weeks post intervention). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05766774, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Jun 2026.