HealthyREPETONCT07675603
Low-carbohydrate Diet and Low-Density Lipoprotein - Cholesterol (LDL-c) Interindividual Variability
A study testing Low carbohydrate diet in people with Healthy, run by University of Bath at 1 site in United Kingdom.
Trial summary
Ketogenic diets are very low-carbohydrate diets that increase hepatic production of ketone bodies, which have several effects as substrates and signals. Ketogenic diets are used to manage some conditions (e.g., drug-resistant epilepsy), and their potential for managing many other conditions (e.g., cancer) is being… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Low carbohydrate diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 5 Feb 2026to Mar 2027
- 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
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age: >18 years
- Body mass index: 18.5-35 kg·m-2
- Low-Density Lipoprotein-cholesterol <4.9 mmol/L
- Non-fasting triglycerides <2.3 mmol/L
Who cannot join
- weight instability (>5% change in body mass within last 3 months)
- smoker
- diagnosis of hypercholesterolaemia or any other lipid-related disease
- diagnosis of diabetes
- diagnosis of atherosclerotic cardiovascular disease
- elevated fasting glucose (>5.4 mmol/L)
Show all 12Show fewer
- dietary intolerances or allergies or to other study procedures
- diagnosis of gastrointestinal disorders
- any other condition/medication that could introduce bias to the study
- already following a ketogenic diet
- not willing to follow a ketogenic diet
- unable to understand English language
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
University of Bath
Bath, Bath and North East Somerset, BA2 7AY
Bruno Spellanzon, PhD candidate, 447769407954, bs954@bath.ac.uk
Javier Gonzalez, PhD, jg833@bath.ac.uk
About this study
Official title: Exploring True Interindividual Heterogeneity of Cardiovascular Disease (CVD) Risk Factors in Response to Low-carbohydrate Diets Using a Replicate Crossover Randomised Controlled Trial
Ketogenic diets are very low-carbohydrate diets that increase hepatic production of ketone bodies, which have several effects as substrates and signals. Ketogenic diets are used to manage some conditions (e.g., drug-resistant epilepsy), and their potential for managing many other conditions (e.g., cancer) is being actively explored. Indeed, the British Dietetic Association acknowledge the potential for ketogenic diets to improve glycaemic control to a greater extent than some other diets in people with type 2 diabetes. A lower fasting glucose is also relevant to future mortality in people without diabetes. Ketogenic diets are popular in the general population, with up to 15% of the UK following a low-carbohydrate diet. There is, therefore, great interest in ketogenic diets amongst people with and without health conditions. However, although the diet shows promising results in improving blood sugar levels, it has also shown to increase low-density lipoprotein-cholesterol (LDL-c) in some individuals, which has been linked to increased cardiovascular health risks. The aim of this project is to find the potential for personalised use of (or guidance to avoid) ketogenic diets for cardiovascular disease risk. To do that the investigators will ask participants to replicate 24 hours of a ketogenic diet and a control diet thrice each. This will allow the investigators to find variability between responses and have a better idea of individuals who could benefit (or not) from following the ketogenic diet.
Read the detailed description
The study will be a controlled feeding replicate randomised controled trial with 3 cycles, each involving the pair of diets [low carbohydrate (K) and control (C) diets]. There will be 6 x 1-day periods (3 days low carbohydrate and 3 days control). Twenty individuals (body mass index: 18.5-35 kg/m2) will be recruited and randomised into one of the 8 possible sequences:
- KC KC KC
- KC KC CK
- KC CK KC
- KC CK CK
- CK CK CK
- CK CK KC
- CK KC CK
- CK KC KC A week before the interventions start, participants will visit the laboratory so that the investigators can perform indirect calorimetry and collect a blood sample for genotyping. During the week before the interventions, participants will wear activity monitors to determine habitual physical activity. Before each visit, participants will be asked to come to the lab in a rested and overnight fasted state. During the first trial visit, participants will have a dual-energy X-ray absorptiometry (DEXA) body scan to determine body composition. During all 12 study visits the investigators will perform a venepuncture in an antecubital vein and will collect 20 mL of blood.
Additionally, the investigators will also collect urine samples. After odd visits (1st, 3rd, 5th, 7th, 9th and 11th), participants will be supplied with their respective meals for the day (low carbohydrate or control) and will be asked to not eat anything else during the day.
Finally there will be a wash-out period of 6 days between laboratory visits. To keep consistency between trial days, participants will be asked to replicate physical activity levels performed during the 24 hours before the first trial, and during diet day (before second visit), so that these can be replicated for the following visits.
- Conditions
- Healthy
- Being tested
- control diet, Low carbohydrate diet
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
control dietOther
Diet will have macronutrients split with 50% carbohydrates, 15% protein and 35% fat. Also there will be a 0.66 ratio saturated:unsaturated fat
Low carbohydrate dietOther
Diet will have macronutrients split with 8% carbohydrates, 15% protein and 77% fat. Also there will be a 0.66 ratio saturated:unsaturated fat
| Study group | Role | What they receive |
|---|---|---|
| Sequence 1 | Other | Participants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 2 | Other | Participants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 3 | Other | Participants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 4 | Other | Participants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 5 | Other | Participants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 6 | Other | Participants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 7 | Other | Participants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet Receives: Other: control diet; Other: Low carbohydrate diet |
| Sequence 8 | Other | Participants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet Receives: Other: control diet; Other: Low carbohydrate diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fasted plasma Low-density lipoprotein cholesterol (LDL-C) concentrations
Variable will be used to establish whether there is true inter-individual heterogeneity in response to 24 hours of a low-carbohydrate diet.
Measured in mmol/L.
Measured: Pre and post following each intervention/control diet for 24 hours
Secondary outcomes (1)
Fasted glucose plasma glucose concentration
Variable measured to establish whether there is true inter-individual heterogeneity in response to 24 hours of a low-carbohydrate diet.
Measured in mmol/L
Measured: Pre and post following each intervention/control diet for 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jun 2026
- Study start5 Feb 2026
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- It will be a replicate crossover, therefore, participants will do each condition (Low carbohydrate diet and Control) 3 times each with a wash-out period between each intervention.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Bath
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Bruno Spellanzon, University of Bath
- Investigators
- Javier Gonzalez, PhD, Principal investigator, University of Bath
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07675603
- Sponsor's protocol ID
- 8791-12081
- Acronym
- REPETO
- Status last verified
- Jun 2026
- First submitted
- 5 May 2026
- Last updated
- 30 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Exploring True Interindividual Heterogeneity of Cardiovascular Disease (CVD) Risk Factors in Response to Low-carbohydrate Diets Using a Replicate Crossover Randomised Controlled Trial
- ClinicalTrials.gov ID
- NCT07675603
- Acronym / sponsor ID
- REPETO / 8791-12081
- Conditions
- Healthy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of BathUniversity, hospital or other
- Study start
- 5 Feb 2026 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 30 Jun 2026 (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.
Ketogenic diets are very low-carbohydrate diets that increase hepatic production of ketone bodies, which have several effects as substrates and signals. Ketogenic diets are used to manage some conditions (e.g., drug-resistant epilepsy), and their potential for managing many other conditions (e.g., cancer) is being actively explored. Indeed, the British Dietetic Association acknowledge the potential for ketogenic diets to improve glycaemic control to a greater extent than some other diets in people with type 2 diabetes. A lower fasting glucose is also relevant to future mortality in people without diabetes. Ketogenic diets are popular in the general population, with up to 15% of the UK following a low-carbohydrate diet. There is, therefore, great interest in ketogenic diets amongst people with and without health conditions. However, although the diet shows promising results in improving blood sugar levels, it has also shown to increase low-density lipoprotein-cholesterol (LDL-c) in some individuals, which has been linked to increased cardiovascular health risks. The aim of this project is to find the potential for personalised use of (or guidance to avoid) ketogenic diets for cardiovascular disease risk. To do that the investigators will ask participants to replicate 24 hours of a ketogenic diet and a control diet thrice each. This will allow the investigators to find variability between responses and have a better idea of individuals who could benefit (or not) from following the ketogenic diet.
Detailed description
The study will be a controlled feeding replicate randomised controled trial with 3 cycles, each involving the pair of diets [low carbohydrate (K) and control (C) diets]. There will be 6 x 1-day periods (3 days low carbohydrate and 3 days control). Twenty individuals (body mass index: 18.5-35 kg/m2) will be recruited and randomised into one of the 8 possible sequences:
- KC KC KC
- KC KC CK
- KC CK KC
- KC CK CK
- CK CK CK
- CK CK KC
- CK KC CK
- CK KC KC A week before the interventions start, participants will visit the laboratory so that the investigators can perform indirect calorimetry and collect a blood sample for genotyping. During the week before the interventions, participants will wear activity monitors to determine habitual physical activity. Before each visit, participants will be asked to come to the lab in a rested and overnight fasted state. During the first trial visit, participants will have a dual-energy X-ray absorptiometry (DEXA) body scan to determine body composition. During all 12 study visits the investigators will perform a venepuncture in an antecubital vein and will collect 20 mL of blood.
Additionally, the investigators will also collect urine samples. After odd visits (1st, 3rd, 5th, 7th, 9th and 11th), participants will be supplied with their respective meals for the day (low carbohydrate or control) and will be asked to not eat anything else during the day.
Finally there will be a wash-out period of 6 days between laboratory visits. To keep consistency between trial days, participants will be asked to replicate physical activity levels performed during the 24 hours before the first trial, and during diet day (before second visit), so that these can be replicated for the following visits.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 8
- Model description
- It will be a replicate crossover, therefore, participants will do each condition (Low carbohydrate diet and Control) 3 times each with a wash-out period between each intervention.
| Arm | Type | Receives |
|---|---|---|
| Sequence 1 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet |
| Sequence 2 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet |
| Sequence 3 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet |
| Sequence 4 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) low-carbohydrate diet, wash-out, 2) control diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet |
| Sequence 5 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet |
| Sequence 6 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) control diet, wash-out, 4) low-carbohydrate diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet |
| Sequence 7 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) control diet, wash-out, 6) low-carbohydrate diet |
| Sequence 8 | Other | Other: control diet, Other: Low carbohydrate dietParticipants will follow a 1) control diet, wash-out, 2) low-carbohydrate diet, wash-out, 3) low-carbohydrate diet, wash-out, 4) control diet, wash-out, 5) low-carbohydrate diet, wash-out, 6) control diet |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age: >18 years
- Body mass index: 18.5-35 kg·m-2
- Low-Density Lipoprotein-cholesterol <4.9 mmol/L
- Non-fasting triglycerides <2.3 mmol/L
Key exclusion criteria (12 listed)
- weight instability (>5% change in body mass within last 3 months)
- smoker
- diagnosis of hypercholesterolaemia or any other lipid-related disease
- diagnosis of diabetes
- diagnosis of atherosclerotic cardiovascular disease
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 |
|---|---|---|
| control dietDiet will have macronutrients split with 50% carbohydrates, 15% protein and 35% fat. Also there will be a 0.66 ratio saturated:unsaturated fat | Other | Sequence 1, Sequence 2, Sequence 3, Sequence 4, Sequence 5, Sequence 6, Sequence 7, Sequence 8 |
| Low carbohydrate dietDiet will have macronutrients split with 8% carbohydrates, 15% protein and 77% fat. Also there will be a 0.66 ratio saturated:unsaturated fat | Other | Sequence 1, Sequence 2, Sequence 3, Sequence 4, Sequence 5, Sequence 6, Sequence 7, Sequence 8 |
Primary outcome
Fasted plasma Low-density lipoprotein cholesterol (LDL-C) concentrations
Time frame: Pre and post following each intervention/control diet for 24 hours
Variable will be used to establish whether there is true inter-individual heterogeneity in response to 24 hours of a low-carbohydrate diet. Measured in mmol/L.
1 secondary outcome
Fasted glucose plasma glucose concentration
Time frame: Pre and post following each intervention/control diet for 24 hours
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 30 Jun 2026.
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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.
Javier Gonzalez, PhD principal investigator
University of Bath
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 carbohydrate diet in people with Healthy, run by University of Bath at 1 site in United Kingdom.
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 4 inclusion and 12 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 30 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 Kingdom. 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 Bruno Spellanzon, PhD candidate (447769407954, bs954@bath.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fasted plasma Low-density lipoprotein cholesterol (LDL-C) concentrations (time frame: Pre and post following each intervention/control diet for 24 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 30 Jun 2026.