Dietary optimisation as a defence against gestational diabetes
| ISRCTN | ISRCTN77245085 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN77245085 |
| Integrated Research Application System (IRAS) | 341490 |
| Central Portfolio Management System (CPMS) | 61413 |
| Sponsor | University of Leicester |
| Funder | Medical Research Council |
- Submission date
- 05/12/2025
- Registration date
- 13/03/2026
- Last edited
- 13/03/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Pregnancy and Childbirth
Plain English summary of protocol
Background and study aims
Each year, 20 million pregnant women globally, including about 100,000 women in the UK, develop gestational diabetes (GDM) (high blood sugar that begins during pregnancy). This can carry health risks for the mother and baby during pregnancy and later in life and leads to huge challenges in stretched healthcare services.
In pregnancy, the mother’s body must adapt to supply fuel and nutrients to the baby. Placenta hormones cause glucose (sugar) to be available for the baby by reducing how well the mother’s insulin works. In most women, this change is balanced by making more insulin to keep blood glucose levels stable. However, some women can’t increase how much insulin they make so blood glucose levels increase, causing gestational diabetes.
We don’t fully understand why some bodies can make more insulin in pregnancy, while others cannot. There are some genetic causes of this, which cannot be changed. However, there must also be non-genetic causes because only about half of women who have gestational diabetes have it again in their next pregnancy. Understanding non-genetic causes may help to find new ways of preventing or managing gestational diabetes.
Previous work by the study team involved a study that recruited 425 participants who had already been diagnosed with GDM. This two-arm, randomised, controlled trial compared a reduced energy diet to a control diet, provided to the participants in the form of ‘diet boxes’ during the last 8–10 weeks of their pregnancy.
In this study we hope to find out if changing diet and body composition in early pregnancy can change the body’s ability to control glucose levels in pregnancy. We will do this through an experimental study using diets designed to reduce body fat (calorie-restricted diet; 1200 kcal) or change where the body stores fat (carbohydrate-restricted diet; 2000 kcal with 25% carbohydrate) and compare these to a control/standard diet (2000 kcal).
Who can participate?
We will recruit 75 women from diverse backgrounds who are ≤16 weeks’ pregnant with high risk of gestational diabetes.
What does the study involve?
At baseline, we will measure the participant's body composition, usual diet, and physical activity. We will then randomise the women into three diet groups: 1) control, 2) reduced-calorie and 3) reduced-carbohydrate. The diets will be supplied weekly to participants’ homes from 12-16 to 24-28 weeks of pregnancy. The participants will return for follow-up data collection at appointments which align with their routine clinical care at 20, 24-28, and 36 weeks of pregnancy and at 3, 12 and 24 months after their baby is born.
What are the possible benefits and risks of participating?
Participants in this study will receive food, free of charge, which is designed to be safe, healthy and provide all the nutrients they, and their growing baby need in pregnancy.
They will be tested for gestational diabetes early in their pregnancy. This means they have the opportunity to be treated earlier and have better outcomes if they do develop it. Additional ultrasound and MRI scans will mean that participants get to see their baby’s development more often than they would during routine antenatal care.
In addition to the evidence showing that people who take part in clinical research studies benefit from the extra input from healthcare professionals, if this study is successful, the diets could lead to short- and long-term improvements in health for both mothers and their babies.
The risks of taking part in this study are low. The small volume of extra blood required will not be a risk to mother or baby. The risks of having a small calorie or carbohydrate restriction in otherwise healthy women with pre-pregnancy overweight or obesity are thought to be very minimal. Dietboxes provide all the required nutrients for a healthy pregnancy and meet appropriate guidelines. Wearing a sensor for glucose (sugar) could be inconvenient for some women but most people do not find this troublesome.
Taking part in the study will not mean attending more clinic visits compared to usual pregnancy care although it will slightly increase the length of these clinic visits.
Where is the study run from?
The study is recruiting participants from University Hospitals of Leicester NHS Trust and is run from Leicester Diabetes Centre. It is sponsored by University of Leicester (UK).
When is the study starting and how long is it expected to run for?
May 2026 to December 2030
Who is funding the study?
Medical Research Council (UK)
Who is the main contact?
Sylvia Brooks (Trial Manager), uhl-tr.dodgediabetes.nhs.uk
Contact information
Principal investigator
Leicester Diabetes Centre
Leicester General Hospital
Leicester
LE5 4PW
United Kingdom
 ORCID ID |
0000-0002-4176-8329 |
|---|---|
| Phone | +44 (0)1162584023 |
| cm881@leicester.ac.uk |
Public
Leicester Diabetes Centre
Leicester General Hospital
Leicester
LE5 4PW
United Kingdom
| Phone | +44 (0)116 258 4023 |
|---|---|
| uhl-tr.dodgediabetes@nhs.net |
Scientific
Leicester Diabetes Centre
Leicester General Hospital
Leicester
LE5 4PW
United Kingdom
| ORCID ID |
0009-0008-3164-1106 |
|---|---|
| Phone | +44 (0)1162584023 |
| laura.kusinski@leicester.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Single-site open-label randomized controlled trial |
| Secondary study design | Randomised controlled trial |
| Scientific title | Maternal diet, body composition and metabolic adaptation to pregnancy |
| Study acronym | DODGE Diabetes |
| Study objectives | Can reduced calorie and/or reduced carbohydrate diets, delivered to pregnant individuals, who are at high risk of developing gestational diabetes, for a 12 week period, during 12 - 28 weeks of pregnancy, effect maternal glycaemia at 24 -28 weeks gestation. |
| Ethics approval(s) |
Not yet submitted |
| Health condition(s) or problem(s) studied | Gestational diabetes |
| Intervention | 75 pregnant individuals, at high risk of developing gestational diabetes will be recruited and randomised (25 in each arm) to receive one of three dietary interventions in the form of dietboxes containing breakfast, lunch, evening meal and a snack for each day and for around 10 - 12 weeks. The interventions are: 1. Control: standard diet (2000 kCal; 40% carbohydrate, 35% fat, 25% protein) 2. Active intervention 1: calorie restricted diet (1200 kCal; 40% carbohydrate, 35% fat, 25% protein) 3. Active intervention 2: carbohydrate-restricted diet (2000 kCal; 25% carbohydrate, 50% fat, 25% protein) Randomisation will occur at the end of the baseline visit and will be stratified by BMI (<40 kg/m2; ≥40 kg/m2) and ethnicity (White ethnicity; Non-White ethnicity). The statistical software package Stata has been used to create four randomisation lists (excel spreadsheets), reflecting the stratification. This will be held by the study manager / administrator who will receive a randomisation call from the clinical team once valid informed consent and baseline data collection is complete. The allocation will be made on a sequential basis from number 1 upwards. The clinical team will be advised of the unique study ID and randomisation allocation and will pass this information onto the participant. The randomisation list will also be shared with the food ordering web-page designer so that the correct meals can be allocated. A paper copy of the randomisation lists will be stored in the master site file and updated after each randomisation. This paper copy will be available for use if access to the version stored electronically is not possible. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
Maternal fasting glycaemia measured by a fasting blood sample taken at the time of the 24 - 28 week oral glucose tolerance test (OGTT) |
| Key secondary outcome measure(s) |
1. Maternal fasting glycaemia measured by a fasting blood sample taken at the time of the baseline (≤16 weeks of pregnancy) oral glucose tolerance test (OGTT) |
| Completion date | 31/12/2030 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 100 Years |
| Sex | Female |
| Target sample size at registration | 75 |
| Key inclusion criteria | 1. Pregnant people aged ≥18 years 2. BMI >25 kg/m2 3. Confirmed pregnancy (≤16 week’s gestation) 4. ≥1 risk factor for GDM (e.g., obesity, family history of diabetes, previous GDM, previous large baby weighing >4.5 kg, ethnicity at high risk of diabetes, or polycystic ovary syndrome) 5. Willing and able to consent to participate in the trial, with support from an interpreter if needed 6. Planned antenatal care at the same study centre, throughout their pregnancy (i.e. not planning to move away from the region before delivery) |
| Key exclusion criteria | 1. Women with evidence of multiple pregnancies 2. Termination planned 3. Pre-existing comorbidities such as renal failure, severe liver disease, cardiac failure, and psychiatric conditions requiring inpatient admission 4. Medications at the time of recruitment that may interfere with results (e.g., high-dose steroids, immunosuppressants). 5. Severe anaemia at the time of recruitment 6. Confirmed diagnosis of existing type 1 or type 2 diabetes mellitus 7. Haemoglobin A1c (HbA1c) at time of recruitment, indicative of GDM of >48 mmol/mol 8. Specialised dietary requirement (e.g., vegan or severe nut allergy) |
| Date of first enrolment | 01/05/2026 |
| Date of final enrolment | 30/04/2028 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Infirmary Square
Leicester
LE1 5WW
England
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not expected to be made available |
| IPD sharing plan |
Editorial Notes
08/12/2025: Study's existence confirmed by the Medical Research Council.
