LOGIC (LOw carbohydrate diets for Glucose Control in type 2 diabetes)
| ISRCTN | ISRCTN33756948 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN33756948 |
| IRAS number | 334413 |
| Secondary identifying numbers | CPMS 58895, IRAS 334413 |
- Submission date
- 12/04/2024
- Registration date
- 17/04/2024
- Last edited
- 02/05/2024
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Type 2 diabetes is a common disease in which a person’s blood glucose levels are too high. We know that what we eat affects our blood glucose levels, and that changing our diets and losing weight can both help to control type 2 diabetes. However, it is not clear what the best advice is to help people achieve this goal. We know that it is possible for some people to improve their blood glucose levels by following a low-carbohydrate diet (cutting out starchy and sugary foods), but it is not clear whether the benefits come from eating less carbohydrate itself, or from losing weight at the same time (from eating less overall). We want to help answer this question by comparing two sorts of low-carbohydrate diets – one designed to help people lose weight at the same time, and one where people stay at the same weight but improve their blood glucose levels by changing the food they eat. This will help us give better advice to people living with type 2 diabetes about what is the right diet for them, to help them achieve their health goals.
Who can participate?
We are looking for 30 people who have type 2 diabetes to take part in this study.
What does the study involve?
This study will compare two types of low-carbohydrate eating plans (reducing the amount of starchy and sugary foods) – one will involve eating the same number of calories as usual each day, and one weight loss diet which will involve reducing the number of calories eaten each day to help weight loss (around 2-4kg over the 4 week diet period).
Participants will be randomly allocated (like tossing a coin) to one of these two eating plans. Food won’t be provided as part of this study, however, we will provide information and support to follow the eating plans at home. Participants will wear a device on their arm which measures blood glucose levels constantly throughout the day and night. Participants will attend three study visits at their local GP practice, where they will meet with one of the research team. During these visits, participants will be asked to answer some questions about diet and medication, complete questionnaires, and give blood samples. With the GP’s approval, we may pause some regular medication at the start of the study to prevent low blood sugar and low blood pressure. Weight and blood pressure will be monitored throughout the study.
What are the possible benefits and risks of participating?
Benefits
- We hope that most people who try the eating plans in this study will see some improvements in their blood glucose levels, which can be beneficial to health and general wellbeing.
- Many people with type 2 diabetes are keen to experience using a continuous glucose monitor (CGM), as these are not usually available on the NHS for this condition but can help with understanding how the diet affects blood glucose levels. Participants will get a 4 week period of CGM if you take part in this study.
- Knowledge gained in this study will help our research and in the future may help us advise people with diabetes about which types of diets might be most helpful for them.
Risks
- There are no known serious risks from the dietary advice that is being given in this study.
- Some people find blood tests temporarily uncomfortable, or that they can develop a small bruise afterwards.
- Some people may experience constipation if they reduce the amount of food they are eating during a weight loss diet, but we will give advice on how to avoid this if allocated to follow the weight loss diet.
- Some people will experience improvements in their blood sugar and/or blood pressure when following these eating plans, which could lead to someone experiencing low blood sugar or low blood pressure levels, but we will monitor blood pressure throughout the study and help manage medication to avoid this.
- If participants take warfarin medication, changes in diet could lead to a changes in INR levels, participants will be advised to inform the team monitoring INR levels that they will be following a new eating plant for 4 weeks and may recommend an additional blood test to monitor for any changes.
Where is the study run from?
This study is being run from GP practices in the Oxfordshire area (UK)
When is the study starting and how long is it expected to run for?
July 2023 to April 2025
Who is funding the study?
This study is funded by the National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) in Oxford, and the Wellcome Trust (UK)
Who is the main contact?
Dr Sam West, LOGIC@phc.ox.ac.uk
Contact information
Public, Scientific, Principal Investigator
Radcliffe Primary Care Building
Oxford
OX2 6GG
United Kingdom
 ORCID ID |
0000-0002-5432-863X |
|---|---|
| Phone | +44 1865 289120 |
| sam.west@phc.ox.ac.uk |
Study information
| Study design | Observational (pre-post) dietary intervention study with secondary comparison between randomised groups |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised parallel trial |
| Study setting(s) | GP practice |
| Study type | Treatment |
| Participant information sheet | Not available in web format, please use the contact details to request a patient information sheet. |
| Scientific title | Disentangling the contribution of weight loss and diet composition on glycaemia in type 2 diabetes |
| Study acronym | LOGIC |
| Study objectives | We aim to assess whether a low carbohydrate diet can improve glycaemic control in patients with type 2 diabetes with and without weight loss. We hypothesise that we will observe a greater improvement in glycaemic control in the low carbohydrate diet with weight loss group compared with the low carbohydrate diet without weight loss group. |
| Ethics approval(s) |
Approved 07/03/2024, HRA and Health and Care Research Wales (HCRW) (15 Cowbridge Road, Cardiff, CF11 9AB, United Kingdom; +44 2920 230457; HCRW.approvals@wales.nhs.uk), ref: 24/LO/0070 |
| Health condition(s) or problem(s) studied | Type 2 diabetes |
| Intervention | Participants will have blood glucose monitored for 2 weeks before randomisation. Then participants will be randomly allocated to receive: Diet A: Low carbohydrate, low-energy food-based diet 800-1000kcal/day; (<26%% total energy from carbohydrate, absolute carbohydrate content approx. 60-65g/day). Diet B: Low carbohydrate “ad libitum” (eucaloric) diet (no energy restriction, aiming for no significant weight change; estimated 2000-2500kcal/day; <26% total energy from carbohydrate – absolute carbohydrate content approx. 125g/day). The dietary intervention lasts for 4 weeks. |
| Intervention type | Behavioural |
| Primary outcome measure | Glycaemic control measured using continuous glucose monitoring. Participants will wear the monitor for the entire 6-week duration of the study. |
| Secondary outcome measures | 1. Glycaemic control measured using continuous glucose monitoring. Participants will wear the monitor for the entire 6-week duration of the study 2. Cardiometabolic risk - assessed via changes in blood lipids (Total-, HDL-, LDL- cholesterol and triglycerides), liver function (bilirubin, ALT and ALP) and blood pressure at baseline, at the end of the 2-week habitual phase and at the end of the 4-week intervention phase 3. Subjective measures of appetite - assessed using VAS scores for hunger fullness, desire to eat and planned consumption using Ecological Momentary Assessment once per week during the habitual and intervention phase 4. Body composition - assessed as body mass, impedance, waist and hip circumference at baseline, at the end of the 2-week habitual phase and at the end of the 4-week intervention phase |
| Overall study start date | 10/07/2023 |
| Completion date | 28/04/2025 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 70 Years |
| Sex | Both |
| Target number of participants | Planned Sample Size: 30; UK Sample Size: 30 |
| Key inclusion criteria | 1. Participants willing and able to give informed consent. 2. Adult male or female, aged 18-70 years old. 3. Diagnosed with current type 2 diabetes (i.e. not in remission). 4. BMI of > = 27kg/m². 5. Has a smartphone with internet access and compatible with continuous glucose monitoring (CGM) technology, and participant is willing and able to use this. 6. Is willing and able to change their diet for the study period. 7. Willing to pause one or more usual medications if required for duration of study. |
| Key exclusion criteria | 1. Pregnant, breastfeeding, or planning to become pregnant during the course of the study. 2. Recent weight loss (> 2kg in last 4 weeks; self-reported). 3. People who are already following a specific restricted diet. 4. Are currently taking more than two prescribed medications for diabetes glycaemic control. 5. People with HbA1c > = 87 mmol/mol. 6. Are currently using insulin therapy, SGLT2 inhibitors (Gliflozins – eg empaglifozin, dapagliflozin, canagliflozin), or GLP-1 agonists (e.g. exenatide, lixisenatide, liraglutide, dulaglutide and semaglutide). 7. Previous or current eating disorder (or any other psychological condition) that may affect the participant’s ability to adhere to study intervention/experimental diets. 8. Recent myocardial infarction or stroke (< 3 months). 9. Renal failure (chronic kidney disease stage 4 or 5). 10. Current active treatment for cancer (other than skin cancer treated with curative intent by local treatment only). 11. Proliferative diabetic retinopathy, or maculopathy. 12. GP feels inappropriate to take part in study (e.g. unable to attend study visits; end of life care, or would not benefit from weight loss or improved diabetes control). 13. Most recent (non-fasting or fasting) triglyceride level > 5 mmol/l. |
| Date of first enrolment | 15/04/2024 |
| Date of final enrolment | 30/12/2024 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Headley Way
Headington
Oxford
OX3 9DU
United Kingdom
Sponsor information
University/education
Joint Research Office, Boundary Brook House, Churchill Drive
Oxford
OX3 7GB
England
United Kingdom
| Phone | +44 1865 616483 |
|---|---|
| rgea.sponsor@admin.ox.ac.uk | |
| Website | http://www.ox.ac.uk/ |
"ROR" |
https://ror.org/052gg0110 |
Funders
Funder type
Government
Private sector organisation / Research institutes and centers
- Alternative name(s)
- NIHR Biomedical Research Centre, Oxford, OxBRC
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 28/04/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request, Data sharing statement to be made available at a later date |
| Publication and dissemination plan | Planned publication in a high-impact peer-reviewed journal |
| IPD sharing plan | The data sets generated during and/or analysed during the current study will be made available upon request from Dr Sam West (sam.west@phc.ox.ac.uk) |
Editorial Notes
02/05/2024: Internal review.
12/04/2024: Trial's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).
