Researchers studied nearly 2,800 pregnant women to see if eating more plant-based foods early in pregnancy could prevent gestational diabetes—a type of diabetes that develops during pregnancy. Women who ate more whole grains, fruits, vegetables, legumes, nuts, seeds, and olive oil had significantly lower chances of developing gestational diabetes and had healthier blood sugar levels. The study found that for every 10% increase in plant-based food intake, the risk of gestational diabetes dropped by 14%. These findings suggest that eating more plant-based foods early in pregnancy could be an important way to protect both mother and baby’s health.

The Quick Take

  • What they studied: Whether eating more plant-based foods early in pregnancy helps prevent gestational diabetes (a type of diabetes that happens during pregnancy) and improves baby’s health
  • Who participated: 2,770 pregnant women with an average age of about 30 years who were part of a large pregnancy study. Most women were at a healthy weight before pregnancy
  • Key finding: Women who ate the most plant-based foods had a 14% lower chance of developing gestational diabetes for every 10% increase in plant-based food intake. About 13.6% of women in the study developed gestational diabetes, and those eating more plants had much lower rates
  • What it means for you: If you’re planning to become pregnant or are already pregnant, eating more whole grains, fruits, vegetables, beans, nuts, and olive oil may help reduce your risk of gestational diabetes. However, this study shows association, not proof of cause-and-effect, so talk to your doctor about your diet

The Research Details

This was a cohort study, which means researchers followed a large group of pregnant women over time and tracked what they ate and their health outcomes. At the beginning of pregnancy, women filled out detailed questionnaires about their eating habits. Researchers then calculated a score based on how much of their daily food came from plant-based sources like whole grains, fruits, vegetables, beans, nuts, seeds, and olive oil. Between 24-28 weeks of pregnancy, all women were tested for gestational diabetes using a standard glucose tolerance test (a test that measures how well the body handles sugar). Researchers then compared the plant-based food scores of women who developed gestational diabetes with those who didn’t, while accounting for other factors that might affect the results.

This research approach is important because it follows real pregnant women through their actual pregnancies rather than just studying cells in a lab. By measuring diet early in pregnancy and then tracking who develops gestational diabetes later, researchers can see if there’s a real connection. The study also looked at actual health outcomes for both mothers and babies, making the results more meaningful for real-world pregnancy care

This study has several strengths: it included a large number of women (2,770), used a validated food questionnaire to measure diet accurately, and adjusted for many other factors that could affect the results. The study was published in a peer-reviewed journal, meaning other experts reviewed the work. However, the study shows association (things that happen together) rather than proving that eating more plants directly causes lower diabetes risk. Women in this study were relatively healthy with normal pre-pregnancy weights, so results may not apply to all pregnant populations

What the Results Show

Women who ate the most plant-based foods had significantly lower rates of gestational diabetes compared to those who ate the least. The relationship was very clear and consistent—as plant-based food intake increased, gestational diabetes risk decreased. For every 10% increase in the proportion of daily calories from plant-based foods, women had a 14% lower chance of developing gestational diabetes. This means that small increases in eating plants can add up to meaningful protection.

Women with the highest plant-based food intake also had better blood sugar control throughout pregnancy. They had lower fasting blood sugar levels (measured after not eating overnight), lower HbA1c (a measure of average blood sugar over time), and lower blood sugar levels after drinking the glucose test drink. These improvements suggest that plant-based foods help the body manage sugar more effectively.

Beyond gestational diabetes prevention, babies born to mothers with higher plant-based food intake had lower rates of neonatal hypoglycemia (low blood sugar in newborns). Mothers eating more plant-based foods also had healthier cholesterol levels, with lower triglycerides and total cholesterol, and higher HDL cholesterol (the ‘good’ cholesterol). These improvements in the mother’s metabolic health—how her body processes nutrients and energy—likely contribute to better outcomes for both mother and baby

Previous research has suggested that plant-based diets are good for blood sugar control and reducing inflammation, but this is one of the first large studies to specifically look at plant-based eating early in pregnancy and gestational diabetes risk. The findings align with what we know about how plant-based foods help the body manage blood sugar, but this study provides stronger evidence by following real pregnancies and measuring actual outcomes. The magnitude of risk reduction (14% per 10% increase) is substantial and clinically meaningful

This study shows that plant-based eating and lower gestational diabetes risk go together, but it doesn’t prove that eating more plants directly causes the lower risk—other unmeasured factors could be involved. The women in this study were relatively healthy with normal pre-pregnancy weights, so the results may not apply to women who are overweight or have other health conditions. The study was observational, meaning women chose their own diets rather than being randomly assigned to eat differently. Additionally, diet was measured only once at the beginning of pregnancy, so we don’t know if eating patterns changed later

The Bottom Line

If you are planning pregnancy or are currently pregnant, consider increasing your intake of whole grains, fruits, vegetables, legumes (beans and lentils), nuts, seeds, and olive oil. These foods appear to help prevent gestational diabetes and improve overall metabolic health. Aim to gradually increase the proportion of your daily calories from these plant-based sources. This recommendation has moderate confidence based on this study’s findings, though it should be combined with other healthy pregnancy practices like regular physical activity and appropriate weight management. Always discuss dietary changes with your healthcare provider

This research is most relevant for women who are planning to become pregnant or are in early pregnancy. It’s particularly important for women with risk factors for gestational diabetes, such as family history of diabetes, previous gestational diabetes, or overweight status. However, the healthy eating patterns described benefit all pregnant women and their babies. Women who already follow plant-based diets will likely see these benefits. This research may be less directly applicable to women with severe dietary restrictions or certain medical conditions that limit plant food intake

The benefits of eating more plant-based foods appear to develop over the course of early pregnancy. Since gestational diabetes is typically diagnosed between 24-28 weeks of pregnancy, dietary changes made in the first trimester (first three months) have time to influence blood sugar metabolism. You may notice improved energy levels and digestion within weeks of increasing plant foods, but the metabolic benefits that prevent gestational diabetes develop over months. If you’re already pregnant, it’s not too late to make dietary improvements

Want to Apply This Research?

  • Track daily servings of plant-based foods by category: whole grains (target 3-4 servings), vegetables (target 4-5 servings), fruits (target 2-3 servings), legumes (target 1-2 servings), nuts/seeds (target 1 serving), and olive oil use. Log these daily and aim for consistency across the week
  • Start by adding one plant-based food to each meal: add berries to breakfast, add beans to lunch, add extra vegetables to dinner. Use the app to set reminders to include these foods and track progress. Create a simple shopping list of favorite plant-based foods to make grocery shopping easier and more intentional
  • Use the app to track weekly plant-based food intake patterns and identify which categories you’re meeting and which need improvement. Set a goal to gradually increase plant-based food proportion of daily meals over 4-8 weeks. If you’re pregnant, share your tracking data with your healthcare provider at prenatal visits to discuss dietary progress and any concerns

This research suggests an association between plant-based eating and lower gestational diabetes risk, but does not prove that dietary changes will prevent gestational diabetes in all women. Gestational diabetes is influenced by many factors including genetics, weight, and overall health. This information is for educational purposes and should not replace medical advice from your healthcare provider. All pregnant women should be screened for gestational diabetes as recommended by their doctor. If you have been diagnosed with gestational diabetes or have risk factors, work with your healthcare team and a registered dietitian to develop an appropriate nutrition plan. Do not make significant dietary changes during pregnancy without consulting your healthcare provider first.