PreDiabetesLEAPNCT05235425
The Lifestyle Education About Prediabetes (Leap) Study
A study testing Standard NDPP and Very low-carbohydrate diet in people with PreDiabetes, run by University of Michigan at 1 site in United States.
Trial summary
This research tested whether a standard version or very low-carbohydrate version of the Diabetes Prevention Program better improves outcomes like blood glucose control and body weight for patients with prediabetes. Participants had screening (included blood draw) and baseline testing with a continuous glucose monitor. Read more about this study
- Who is it for?
- Ages 21 to 75 years
- Conditions the study is for
- PreDiabetes
- What is being tested?
- Standard NDPP and Very low-carbohydrate diet
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 304 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Mar 2022to 14 Nov 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 21 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- overweight, defined as BMI ≥ 25 kg/m² or ≥ 23 kg/m² if of Asian descent
- HbA1c 5.7% to 6.4% (as measured in our baseline blood test)
- willingness and ability to participate in group-based, online sessions using audio and video
- ability to engage in at least light physical activities, such as walking
- willingness to follow a prescribed diet, be randomized, self-weigh, track diet, and report physical activity minutes
- physician approval to participate
Who cannot join
- Primary
- history of type 1 diabetes or type 2 diabetes
- use of anti-obesity medications or participation in another weight loss program or intervention
- use of glucose lowering medications other than metformin
- pregnant or planning to become pregnant during the intervention period
- breastfeeding
Show all 28Show fewer
- use of oral corticosteroids
- plan to start a weight loss medication during the study period
- previous bariatric surgery or planning to have bariatric surgery during the study period
- blood disorders that influence HbA1c, including frequent blood transfusions, phlebotomy, anemia, hemoglobinopathy, polycythemia
- any condition for which the study team deems participation to be unsafe or inappropriate
- Ability
- inability to read, write, or speak English
- inability to provide informed consent
- adherence to a vegan or vegetarian diet
- adherence to a very low-carbohydrate (keto) diet
- difficulty chewing or swallowing
- no influence over what foods are purchased, prepared, and/or served
- above weight limit for DEXA (500 lbs)
- Safety
- untreated eating disorder or mental health conditions, such as depression with suicidal ideation, bipolar or schizophrenia with psychosis
- use of warfarin
- chronic kidney disease, stage 4 or higher
- use of loop diuretics: 20mg or higher of furosemide or equivalent (Lasix (furosemide), Bumex (bumetanide), Edecrin or Sodium Edecrin (ethacrynic acid), Demadex or Soaanz (torsemide))
- any concerning values in baseline labs (participants will be referred to PCP and will be allowed to return for later enrollment if labs are no longer concerning):
- triglycerides 600 mg/dL or higher
- TSH of any abnormal value
- Potassium of any abnormal value
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Testing a Very Low-carbohydrate Diet Version of the Diabetes Prevention Program to Reduce Risk Factors for Type 2 Diabetes: The LEAP (Lifestyle Education About Prediabetes) Study
This research tested whether a standard version or very low-carbohydrate version of the Diabetes Prevention Program better improves outcomes like blood glucose control and body weight for patients with prediabetes.
Participants had screening (included blood draw) and baseline testing with a continuous glucose monitor. Once these enrollment steps were completed, the participants were randomized to one of two groups: a standard National Diabetes Prevention Program (NDPP) or a very low-carbohydrate version.
In addition to following the diet for 12 months, participants were asked to participate in hour-long weekly group classes over Zoom. After four months in the program, classes occurred about every month to help participants maintain the new diet. There were also check-ins and follow-up visits throughout the study.
- Conditions
- PreDiabetes
- Being tested
- Standard NDPP, Very low-carbohydrate diet
- Keywords
- Very low carbohydrate diet, Diabetes Prevention Program, Nutrition therapy
- Medical subject headings
- Prediabetic State
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Standard NDPPBehavioural
Participants in this arm were taught to manage their prediabetes with the Centers for Disease Control's standard National Diabetes Prevention Program (NDPP). The NDPP teaches a lower calorie, lower fat diet.
There was a core phase and a maintenance phase of this study; the core phase lasted for about 4 months and involved weekly or every other week classes, home assignments, and brief check-in surveys. The maintenance phase lasted for the remaining time, with classes and check-in surveys approximately once a month.
Very low-carbohydrate dietBehavioural
Participants in this arm were taught to manage their prediabetes with the Centers for Disease Control's National Diabetes Prevention Program, adapted to teach a very low-carbohydrate diet, also called a ketogenic or "keto" diet. This diet involved eating non-starchy vegetables, leafy greens, cheese, meats, berries, nuts, and seeds, and avoiding starchy foods like pasta, bread, rice, beans, and many fruits.
There was a core phase and a maintenance phase of this study; the core phase lasted for about 4 months and involved weekly or every other week classes, home assignments, and brief check-in surveys. The maintenance phase lasted for the remaining time, with classes and check-in surveys approximately once a month.
| Study group | Role | What they receive |
|---|---|---|
| Standard NDPP | Active comparator | 12-month long, calorie-restricted NDPP Receives: Behavioral: Standard NDPP |
| Very low-carbohydrate diet (VLCD) | Experimental | The VLCD was an adaptation of the standard NDPP curriculum, which preserved all features with the exception of altered dietary advice. Receives: Behavioral: Very low-carbohydrate diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in HbA1c
HbA1c is the proportion of hemoglobin in the blood that has glucose attached to it relative to total hemoglobin. It reflects average blood glucose levels over approximately the previous 2-3 months. To assess the effect of dietary intervention on HbA1c, the change in HbA1c from baseline to 12 months was compared between the two diet groups. A negative change indicates an improvement in HbA1c from baseline.
Measured: Baseline, 12 months
Secondary outcomes (11)
Change in Inflammation based on C-reactive protein (CRP)
High-sensitivity C-reactive protein (hsCRP) was measured quantitatively in serum using a latex immunoturbidimetric assay. Levels of hsCRP are considered a measure of systemic inflammation, with higher levels indicating more inflammation. To assess the effect of dietary intervention on hsCRP, the change in hsCRP from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in hsCRP from baseline.
Measured: Baseline, 12 months
Change in percent body weight
Percentage change in body weight. Body weight data were collected using at-home scales. Percentage change in body weight from baseline to 12 months was calculated as the difference between body weight at 12 months and baseline, divided by baseline body weight and multiplied by 100. A negative percentage change indicates a decrease in body weight from baseline. The percentage change in body weight was compared between the two diet groups.
Measured: Baseline, 12 months
Change in glycemic variability (SD)
Glucose levels were measured using an Abbott Libre Pro continuous glucose monitoring device that was worn on the participant's upper arm, with glucose data masked to participants. The monitoring device recorded glucose levels in the interstitial fluid using a glucose oxidase method every 15 minutes, continuously for 14 days at each timepoint. Glucose variability was calculated as the standard deviation (SD) of glucose from the continuous glucose monitoring data. The change in glucose variability (SD) from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in glucose variability from baseline.
Measured: Baseline, 12 months
Change in glycemic variability (coefficient of variation)
Glucose levels were measured using an Abbott Libre Pro continuous glucose monitoring device that was worn on the participant's upper arm, with glucose data masked to participants. The monitoring device recorded glucose levels in the interstitial fluid using a glucose oxidase method every 15 minutes, continuously for 14 days at each timepoint. Glucose variability was calculated as the coefficient of variation (CV), defined as the SD of glucose divided by mean glucose × 100%, from the continuous glucose monitoring data. The change in glucose variability (CV) from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in glucose variability from baseline.
Measured: Baseline, 12 months
Change in the proportion of time in very tight range
Glucose levels were measured using an Abbott Libre Pro continuous glucose monitoring device that was worn on the participant's upper arm, with glucose data masked to participants. The monitoring device recorded participants' glucose levels in the interstitial fluid using a glucose oxidase method every 15 minutes, continuously for 14 days at each timepoint. The proportion of time in very tight range (70-120 mg/dL) was calculated. The change in the proportion of time in tight range from baseline to 12 months was compared between the two diet groups. A positive change indicates an increase in the proportion of time in very tight range from baseline.
Measured: Baseline, 12 months
Change in the proportion of time above range
Glucose levels were measured using an Abbott Libre Pro continuous glucose monitoring device that was worn on the participant's upper arm, with glucose data masked to participants. The device recorded glucose levels in the interstitial fluid using a glucose oxidase method every 15 minutes, continuously for 14 days at each time point. The proportion of time above range (glucose >140 mg/dL for at least 15 minutes) was calculated. The change in the proportion of time above range from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in the proportion of time above range from baseline.
Measured: Baseline, 12 months
Change in small particle low-density lipoproteins (LDL)
Small LDL particle concentration (small LDL-P) was measured using nuclear magnetic resonance (NMR) spectroscopy. Higher concentrations of small LDL-P have been associated with increased cardiovascular risk. To assess the effect of dietary intervention on small LDL-P, the change in small LDL-P from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in small LDL-P from baseline.
Measured: Baseline, 12 months
Change in high-density lipoproteins (HDL)
HDL cholesterol levels were measured using nuclear magnetic resonance (NMR) spectroscopy. Lower HDL levels have been associated with increased cardiovascular risk. To assess the effect of dietary intervention on HDL, the change in HDL from baseline to 12 months was compared between the two diet groups. A positive change indicates an increase in HDL from baseline.
Measured: Baseline, 12 months
Change in triglycerides
Triglyceride levels were measured using nuclear magnetic resonance (NMR) spectroscopy. Higher concentrations of triglycerides have been associated with increased cardiovascular risk. To assess the effect of dietary intervention on triglycerides, the change in triglycerides from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in triglycerides from baseline.
Measured: Baseline, 12 months
Change in percent body fat on DEXA
Percent body fat was assessed in percentage using Dual Energy x-ray absorptiometry (DEXA). The change in percent body fat from baseline to 12 months was compared between the two diet groups. A negative change indicates a decrease in percent body fat from baseline.
Measured: Baseline, 12 months
Change in HbA1c
HbA1c is the proportion of hemoglobin in the blood that has glucose attached to it relative to total hemoglobin. It reflects average blood glucose levels over approximately the previous 2-3 months. To assess the effect of dietary intervention on HbA1c, the change in HbA1c from baseline to 4 months was compared between the two diet groups. A negative change indicates an improvement in HbA1c from baseline.
Measured: Baseline, 4 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Feb 2022
- Study start20 Mar 2022
- Primary completion14 Nov 2025
- Study completion14 Nov 2025
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 PreDiabetesStudies of the same condition, open and under way.
- More trials run by University of MichiganThe 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 304 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Laura Saslow, University of Michigan
- Investigators
- Laura Saslow, PhD, Principal investigator, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05235425
- Sponsor's protocol ID
- HUM00196546
- Other IDs
- R01DK125792-01A1
- Acronym
- LEAP
- Status last verified
- Oct 2026
- First submitted
- 2 Feb 2022
- Last updated
- 6 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Griauzde DH, O'Brien A, Yancy WS Jr, Richardson CR, Krinock J, DeJonckheere M, Isaman DJM, Vanias K, Shopinski S, Saslow LR. Testing a very low-carbohydrate adaption of the Diabetes Prevention Program among adults with prediabetes: study protocol for the Lifestyle Education about prediabetes (LEAP) trial. Trials. 2022 Sep 30;23(1):827. doi: 10.1186/s13063-022-06770-3.
PubMed 36176003
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Testing a Very Low-carbohydrate Diet Version of the Diabetes Prevention Program to Reduce Risk Factors for Type 2 Diabetes: The LEAP (Lifestyle Education About Prediabetes) Study
- ClinicalTrials.gov ID
- NCT05235425
- Acronym / sponsor ID
- LEAP / HUM00196546
- Conditions
- PreDiabetes
- Keywords
- Very low carbohydrate diet, Diabetes Prevention Program, Nutrition therapy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 304 participants (actual)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 20 Mar 2022 (actual)
- Primary completion
- 14 Nov 2025 (actual)
- Study completion
- 14 Nov 2025 (actual)
- First posted
- 11 Feb 2022 (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.
This research tested whether a standard version or very low-carbohydrate version of the Diabetes Prevention Program better improves outcomes like blood glucose control and body weight for patients with prediabetes.
Participants had screening (included blood draw) and baseline testing with a continuous glucose monitor. Once these enrollment steps were completed, the participants were randomized to one of two groups: a standard National Diabetes Prevention Program (NDPP) or a very low-carbohydrate version.
In addition to following the diet for 12 months, participants were asked to participate in hour-long weekly group classes over Zoom. After four months in the program, classes occurred about every month to help participants maintain the new diet. There were also check-ins and follow-up visits throughout the study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard NDPP | Active comparator | Behavioral: Standard NDPP12-month long, calorie-restricted NDPP |
| Very low-carbohydrate diet (VLCD) | Experimental | Behavioral: Very low-carbohydrate dietThe VLCD was an adaptation of the standard NDPP curriculum, which preserved all features with the exception of altered dietary advice. |
Who may qualify
- Ages
- 21 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- overweight, defined as BMI ≥ 25 kg/m² or ≥ 23 kg/m² if of Asian descent
- HbA1c 5.7% to 6.4% (as measured in our baseline blood test)
- willingness and ability to participate in group-based, online sessions using audio and video
- ability to engage in at least light physical activities, such as walking
- willingness to follow a prescribed diet, be randomized, self-weigh, track diet, and report physical activity minutes
Key exclusion criteria (28 listed)
- Primary
- Ability
- Safety
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 |
|---|---|---|
| Standard NDPPParticipants in this arm were taught to manage their prediabetes with the Centers for Disease Control's standard National Diabetes Prevention Program (NDPP). The NDPP teaches a lower calorie, lower fat diet. There was a core phase and a maintenance phase of this study; the core phase lasted for about 4 months and involved weekly or every other week classes, home assignments, and brief check-in surveys. The maintenance phase lasted for the remaining time, with classes and check-in surveys approximately once a month. | Behavioural | Standard NDPP |
| Very low-carbohydrate dietParticipants in this arm were taught to manage their prediabetes with the Centers for Disease Control's National Diabetes Prevention Program, adapted to teach a very low-carbohydrate diet, also called a ketogenic or "keto" diet. This diet involved eating non-starchy vegetables, leafy greens, cheese, meats, berries, nuts, and seeds, and avoiding starchy foods like pasta, bread, rice, beans, and many fruits. There was a core phase and a maintenance phase of this study; the core phase lasted for about 4 months and involved weekly or every other week classes, home assignments, and brief check-in surveys. The maintenance phase lasted for the remaining time, with classes and check-in surveys approximately once a month. | Behavioural | Very low-carbohydrate diet (VLCD) |
Primary outcome
Change in HbA1c
Time frame: Baseline, 12 months
HbA1c is the proportion of hemoglobin in the blood that has glucose attached to it relative to total hemoglobin. It reflects average blood glucose levels over approximately the previous 2-3 months. To assess the effect of dietary intervention on HbA1c, the change in HbA1c from baseline to 12 months was compared between the two diet groups. A negative change indicates an improvement in HbA1c from baseline.
11 secondary outcomes
Change in Inflammation based on C-reactive protein (CRP)
Time frame: Baseline, 12 months
Change in percent body weight
Time frame: Baseline, 12 months
Change in glycemic variability (SD)
Time frame: Baseline, 12 months
Change in glycemic variability (coefficient of variation)
Time frame: Baseline, 12 months
Change in the proportion of time in very tight range
Time frame: Baseline, 12 months
Change in the proportion of time above range
Time frame: Baseline, 12 months
Change in small particle low-density lipoproteins (LDL)
Time frame: Baseline, 12 months
Change in high-density lipoproteins (HDL)
Time frame: Baseline, 12 months
Change in triglycerides
Time frame: Baseline, 12 months
Change in percent body fat on DEXA
Time frame: Baseline, 12 months
Change in HbA1c
Time frame: Baseline, 4 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Oct 2026.
- Derived from this study: PubMed 36176003Griauzde DH, O'Brien A, Yancy WS Jr, Richardson CR, Krinock J, DeJonckheere M, Isaman DJM, Vanias K, Shopinski S, Saslow LR. Testing a very low-carbohydrate adaption of the Diabetes Prevention Program among adults with prediabetes: study protocol for the Lifestyle Education about prediabetes (LEAP) trial. Trials. 2022 Sep 30;23(1):827. doi: 10.1186/s13063-022-06770-3.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Laura Saslow, PhD principal investigator
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Standard NDPP and Very low-carbohydrate diet in people with PreDiabetes, run by University of Michigan 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 6 inclusion and 28 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: finished, as of the sponsor's last update on 6 Oct 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in HbA1c (time frame: Baseline, 12 months). 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 NCT05235425, 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 6 Oct 2026.