Maternal diet, body composition and metabolic adaptation to pregnancy
Gestational diabetes
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.
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)
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)