CompletedInterventional

Dietary intervention in gestational diabetes

Gestational diabetes affects around 35,000 pregnant women in the UK each year. It can cause babies to grow larger than usual, which can make labour and delivery more difficult. Currently, NHS guidelines do not give clear calorie targets for women with the condition. The DiGest study is testing whether a balanced, lower-calorie diet in late pregnancy improves health outcomes for mothers and their babies. Pregnant women who are overweight and have gestational diabetes receive all their daily meals in free food boxes from week 30 until delivery. Half receive standard-calorie meals and half receive reduced-calorie meals. Researchers will track blood sugar levels, weight changes, and baby birthweights. Normal NHS antenatal care and medications continue as usual. The goal is to see if simple dietary changes can reduce birth complications and improve long-term health for mothers.

At a glance

Status

Completed

Sponsor

Cambridge University Hospitals NHS Foundation Trust

Enrolment target

380

Start

01 Nov 2019

Estimated completion

28 Jul 2023

Gestational diabetes

What is this study about?

Gestational diabetes is high blood sugar that develops during pregnancy, affecting around 35,000 women in the UK each year. When blood sugar levels stay higher than normal, babies can grow larger than expected. This can lead to difficult deliveries, a higher chance of needing an emergency caesarean section, and health challenges for both mother and child.

Carrying extra weight before pregnancy increases the risk of developing gestational diabetes. However, doctors still do not know the best amount of weight to gain after diagnosis, which usually happens around week 28. At present, national guidelines do not provide clear daily calorie goals for expectant mothers with the condition.

Early evidence suggests that avoiding too much weight gain in late pregnancy may lead to safer births, healthier infant weights, and better blood sugar control after delivery. This trial, called the DiGest study, is investigating whether eating ready-made, calorie-controlled meals for 8 to 10 weeks before birth makes a meaningful difference to mother and baby.

By comparing a reduced-calorie diet with a standard-calorie diet, researchers hope to create clear nutritional guidelines for the NHS. In the long run, this could help pregnant women manage their blood sugar safely and lower their future risk of developing type 2 diabetes.

Key takeaways

Tests whether a reduced-calorie diet in late pregnancy improves health outcomes for mothers with gestational diabetes and their babies.
Open to women diagnosed with gestational diabetes between 20 and 31 weeks who had a pre-pregnancy BMI of 25 or higher.
Provides all daily meals free of charge for 8 to 10 weeks up until delivery.
Works alongside your standard NHS care, regular scans, and prescribed diabetes medicines.
Participation is entirely voluntary, and you can withdraw at any point without your NHS care changing.

Who may be eligible?

This study is open to pregnant women carrying a single baby who have been diagnosed with gestational diabetes between 20 and 31 weeks of pregnancy. To qualify, you must have had a body mass index (BMI) of 25 or higher before pregnancy, which falls into the overweight or obese category. You also need to be planning to have your maternity care at one of the participating NHS hospital trusts.

You cannot take part if you are pregnant with twins or triplets, or if you had diabetes before becoming pregnant. Women who have certain serious pre-existing health conditions, such as severe heart, liver, or kidney problems, are not eligible. The study also excludes anyone taking medications that affect blood sugar, such as steroid tablets.

Because all meals are pre-cooked and delivered to your home, you cannot participate if you have severe food allergies (such as a life-threatening nut allergy) or require a specialised diet, such as a vegan diet. Women whose babies are already measuring smaller than average at diagnosis are also excluded to protect the baby's growth.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 20 and 31 weeks pregnant with a single baby?
Have you been diagnosed with gestational diabetes during this pregnancy?
Was your body mass index (BMI) 25 or above before becoming pregnant?
Are you receiving your maternity care at a participating NHS hospital?
Can you eat pre-prepared meals without needing a vegan diet or having severe food allergies?

Answer every question to see your result.

What does participation involve?

If you take part, you will be placed by chance into one of two groups: one receives standard-calorie meal boxes, and the other receives reduced-calorie meal boxes. Neither you nor the study team will know which box you get. All your daily meals will be delivered free of charge from around week 30 of your pregnancy until your baby is born (about 8 to 10 weeks).

You will wear a continuous glucose sensor on your skin to monitor blood sugar, keep a food diary, and use a digital scale to check your weight. You will continue to have all your routine NHS maternity appointments, ultrasound scans, and any prescribed medications, such as insulin or metformin. The study also involves routine blood tests and an optional low-dose body composition scan after delivery. Total involvement lasts through the final weeks of your pregnancy until shortly after birth.

Potential risks and benefits

Taking part provides all your meals for free for 8 to 10 weeks, saving you time, grocery shopping, and cooking. Extra blood tests can also uncover helpful information about your general health, such as cholesterol levels. Potential risks are low: you might feel hungrier than usual or quite full depending on the meals, and glucose sensors or blood tests can cause mild skin tenderness or bruising. Significant weight loss during pregnancy can cause babies to be born smaller than ideal, but the research team will monitor you and your baby very closely with weight checks and ultrasound scans to keep you both safe. You are free to leave the study at any time without giving a reason, and your standard NHS maternity care will not be affected in any way.

Locations (6)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Cambridge University Hospitals NHS Foundation Trust
City only
Cambridge, England
North West Anglia NHS Foundation Trust
City only
Peterborough, England
Norfolk and Norwich University Hospitals NHS Foundation Trust
City only
Norwich, England
Kettering General Hospital NHS Foundation Trust
City only
Kettering, England
East and North Hertfordshire NHS Trust
City only
Stevenage, England
The Princess Alexandra Hospital
Unverified
Harlow, England

Common questions

Do I have to pay for any of the food provided?

No. All study meals are provided and delivered completely free of charge from week 30 until you give birth.

Can I choose which diet box I receive?

No. A computer randomly decides whether you receive the standard-calorie or reduced-calorie meals to ensure the study results are fair and reliable.

Will taking part replace my usual NHS maternity care?

No. You will continue to see your regular midwives and doctors, receive all routine scans, and take any prescribed medicines as normal.

What happens if I need insulin or diabetes tablets?

You can take all recommended diabetes treatments. Your NHS doctors will continue to manage your blood sugar medications throughout the trial.

Is it safe to manage my calories while pregnant?

Yes, under medical supervision. Research shows modest weight management can be beneficial in gestational diabetes, and the team will closely monitor your baby's growth.

How to find out more

Claire Meek

cm881@leicester.ac.uk +44 (0)7504 986426 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.