Low-carbohydrate Diet and Low-Density Lipoprotein - Cholesterol (LDL-c) Interindividual Variability

NCT07675603 | Recruiting

• 1 other identifier: 8791-12081
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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 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.

Conditions

Healthy

Outcome Measures

Primary Outcomes (1)

• 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.

  Pre and post following each intervention/control diet for 24 hours

Secondary Outcomes (1)

• Fasted glucose plasma glucose concentration

  Pre and post following each intervention/control diet for 24 hours

Study Arms (8)

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

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

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

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

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

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

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

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

Other: control diet; Other: Low carbohydrate diet

Interventions

control diet OTHER

Diet will have macronutrients split with 50% carbohydrates, 15% protein and 35% fat. Also there will be a 0.66 ratio saturated:unsaturated fat

Sequence 1; Sequence 2; Sequence 3; Sequence 4; Sequence 5; Sequence 6; Sequence 7; Sequence 8

Low carbohydrate diet OTHER

Diet will have macronutrients split with 8% carbohydrates, 15% protein and 77% fat. Also there will be a 0.66 ratio saturated:unsaturated fat

Sequence 1; Sequence 2; Sequence 3; Sequence 4; Sequence 5; Sequence 6; Sequence 7; Sequence 8

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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)
• 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

Sponsors & Collaborators

• University of Bath: lead

Study Sites (1)

University of Bath

Bath, Bath and North East Somerset, BA2 7AY, United Kingdom

RECRUITING

MeSH Terms

Interventions

Diet, Carbohydrate-Restricted

Intervention Hierarchy (Ancestors)

Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Javier Gonzalez, PhD

  University of Bath

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Bruno Spellanzon, PhD candidate

CONTACT

447769407954; bs954@bath.ac.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: 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.

Study Record Dates

• First Submitted: May 5, 2026
• First Posted: June 30, 2026
• Study Start: February 5, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): March 1, 2027
• Last Updated: June 30, 2026

Record last verified: 2026-06

Locations

GB (1)