Low Calorie Diet Safe and Beneficial in Gestational Diabetes

TOPLINE: 

A reduced-energy diet of 1200 kcal per day proved safe and reduced the need for long-acting insulin therapy in pregnant women with gestational diabetes and body mass index (BMI) ≥ 25. 

METHODOLOGY:

• Researchers conducted a Dietary Intervention in Gestational Diabetes trial to assess the effects of a reduced-energy diet in women with gestational diabetes.
• A total of 425 women with singleton pregnancies and gestational diabetes with a BMI ≥ 25 (maternal age, 33.03 years) were included and randomly assigned to receive either a standard-energy diet of 2000 kcal per day (n = 211) or a reduced-energy intervention diet of 1200 kcal per day (n = 214) from enrolment (at 29 weeks of gestation) until delivery.
• The intervention utilised a whole-diet approach by providing participants with weekly diet boxes (40% carbohydrate, 35% fat, and 25% protein), which ensured consistent macronutrient distribution and sufficient micronutrient intake.
• The primary outcomes were maternal weight change from enrolment to 36 weeks of gestation and offspring birth weight; secondary outcomes included maternal glycaemia, cardiometabolic health, and various neonatal outcomes.
• Outcome data were available for 90.1% of participants at 36 weeks and for 89.8% at delivery.

TAKEAWAY:

• At 36 weeks, no significant difference was found in maternal weight change (P = .623) or standardised birth weight of offspring (P = .962) between the two groups.
• The reduced-energy diet group showed lower requirements for long-acting insulin therapy than the standard-energy diet group (27.5% vs 39.2%; odds ratio, 0.36; P = .003).
• Weight loss (average of 3 kg) in late pregnancy was associated with improved maternal glycaemia, decreased systolic blood pressure, and reduced rates of large-for-gestational-age infants.
• The rates of small-for-gestational-age infants were comparable between the groups and fell within expected limits; no stillbirths, neonatal deaths, or maternal deaths occurred in the reduced-energy diet group.

IN PRACTICE:

“Successful and healthy energy restriction in pregnancy could be achieved using a low-glycaemic-index diet, with plenty of vegetables, lean protein, and some dairy products to ensure sufficient nutrients are included,” the authors wrote.

SOURCE:

The study was led by Laura C. Kusinski, PhD, Leicester Diabetes Centre and Leicester NIHR Biomedical Research Centre, University of Leicester, Leicester, United Kingdom, and was published online on February 19, 2025, in Nature Medicine.

LIMITATIONS: 

Although the study population was more ethnically diverse than the UK population, it still included relatively few women from non-White backgrounds, which may have limited the generalisability of the findings. The control diet boxes included 2000 kcal per day, which may have underestimated the energy needed for weight stability in late pregnancy for this cohort. The intervention period of around 6 weeks may have been too short to observe meaningful changes in primary outcomes.

DISCLOSURES:

This study was supported by the National Institute for Health Research Cambridge Biomedical Research Centre, the Core Biochemical Assay Laboratory, and other institutions. The trial received funding from Diabetes UK. Dexcom provided research support and equipment for this study. The authors declared no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.