Eating foods from more different food groups during pregnancy significantly reduces gestational diabetes risk. According to Gram Research analysis of a 2026 cohort study of 3,026 pregnant women, those eating from 8 or more food groups had substantially lower gestational diabetes rates compared to women eating from fewer groups—those with the lowest diversity (4 or fewer groups) had 58% higher risk. Combining dietary diversity with healthy weight management provides the strongest protection.
A new study of over 3,000 pregnant women found that eating a wider variety of foods during pregnancy significantly reduces the risk of developing gestational diabetes. According to Gram Research analysis, women who ate foods from fewer food groups had up to 58% higher risk of gestational diabetes compared to those with more diverse diets. The research suggests that simply eating more types of foods—combined with healthy weight management—could help protect pregnant women from this common pregnancy complication.
Key Statistics
A 2026 prospective cohort study of 3,026 pregnant women found that those eating from only 4 or fewer food groups had 58% higher risk of gestational diabetes compared to women eating from 8 or more groups.
Among 3,026 pregnant women in the Tongji Maternal and Child Health Cohort study, 357 (11.8%) developed gestational diabetes, with risk increasing significantly as dietary diversity decreased.
A 2026 cohort study found that pregnant women with low dietary diversity (5-7 food groups) had 32% higher gestational diabetes risk compared to those with high diversity (8+ groups).
Research from a 2026 study of over 3,000 pregnant women shows that combining low dietary diversity with being overweight before pregnancy and excessive weight gain creates the highest gestational diabetes risk.
The Quick Take
- What they studied: Whether eating a wider variety of foods during pregnancy helps prevent gestational diabetes (a type of diabetes that develops during pregnancy).
- Who participated: 3,026 pregnant women in China who were tracked from early pregnancy through delivery. Researchers measured what they ate and tested them for gestational diabetes around 6 months into pregnancy.
- Key finding: Women who ate foods from 5-7 different food groups had 32% higher risk of gestational diabetes, while those eating from 4 or fewer groups had 58% higher risk, compared to women eating from 8 or more groups.
- What it means for you: Eating a diverse diet with many different types of foods during pregnancy may help reduce your risk of developing gestational diabetes. This is especially important if you’re overweight or gaining too much weight during pregnancy. Talk to your doctor about what foods to include.
The Research Details
Researchers followed pregnant women from the Tongji Maternal and Child Health Cohort in China throughout their pregnancies. They asked women about their eating habits using food questionnaires and 24-hour food recalls (where women describe everything they ate in one day). The researchers then created a “dietary diversity score” by counting how many different food groups each woman ate from—10 groups total including grains, vegetables, fruits, dairy, meat, and others. Between 6-7 months of pregnancy, all women took a glucose tolerance test (a standard test to check for gestational diabetes). The researchers then compared the dietary diversity scores of women who developed gestational diabetes with those who didn’t.
This study design is strong because it followed women forward in time from early pregnancy, measuring their diet before they developed gestational diabetes. This helps prove that diet came first and may have caused the difference in diabetes risk, rather than the other way around. The large sample size of over 3,000 women makes the results more reliable and representative of real-world pregnancies.
This is a well-designed prospective cohort study, which is considered strong evidence in nutrition research. The study measured diet using validated methods and tested all women for gestational diabetes using the standard medical test. The large sample size and clear statistical analysis strengthen the findings. However, the study was conducted in China, so results may not apply equally to all populations worldwide.
What the Results Show
Among 3,026 pregnant women, 357 (about 12%) developed gestational diabetes. Women whose dietary diversity score was 5-7 (eating from 5-7 different food groups) had a 32% higher risk of gestational diabetes compared to women scoring 8 or higher. Women with the lowest diversity scores (4 or fewer food groups) had the highest risk—58% higher than women with the most diverse diets. These differences remained significant even after researchers accounted for other factors like age and pre-pregnancy weight. The protective effect of dietary diversity was strongest in women who were overweight or obese before pregnancy and those who gained excessive weight during pregnancy—these women with low dietary diversity had the very highest risk of gestational diabetes.
The study found that the combination of low dietary diversity plus being overweight before pregnancy plus excessive weight gain during pregnancy created the highest-risk group. This suggests that multiple factors work together to influence gestational diabetes risk. The findings indicate that dietary diversity acts independently—meaning it helps reduce risk even when accounting for weight and other factors.
This research supports previous findings showing that diet quality matters during pregnancy. Earlier studies suggested that eating more whole foods and vegetables reduces gestational diabetes risk. This study adds new evidence that the variety of foods matters, not just the quality. The findings align with international nutrition guidelines that recommend dietary diversity as a key component of healthy eating.
The study was conducted only in China, so results may not apply equally to pregnant women in other countries with different food availability and eating patterns. Researchers relied on women’s memory of what they ate, which can be inaccurate. The study measured diet at one point in time, so it doesn’t show how diet changes throughout pregnancy affect risk. The study cannot prove that dietary diversity directly causes lower gestational diabetes risk—only that they are associated.
The Bottom Line
Pregnant women should aim to eat foods from at least 8 different food groups daily, including whole grains, vegetables, fruits, legumes, nuts, dairy, eggs, and meat or fish. This recommendation has strong evidence support from this study. Women who are overweight or gaining excessive weight during pregnancy should prioritize dietary diversity even more. Discuss specific food choices with your healthcare provider or a registered dietitian who can personalize recommendations for your situation.
All pregnant women should pay attention to these findings, especially those who are overweight, obese, or gaining excessive weight during pregnancy. Women with a family history of diabetes or previous gestational diabetes should be particularly attentive. The findings may be most relevant to women in similar populations to the study (Asian populations), though the basic principle of dietary diversity applies broadly. Women with specific dietary restrictions should work with a dietitian to ensure diversity within their constraints.
Dietary changes can begin immediately and should ideally start before pregnancy or in early pregnancy. The study measured diet around 6 months into pregnancy, suggesting that eating patterns throughout pregnancy matter. Benefits in terms of reduced gestational diabetes risk would be assessed at the standard screening time (24-28 weeks of pregnancy). Long-term, maintaining dietary diversity may also help prevent type 2 diabetes after pregnancy.
Frequently Asked Questions
Can eating different types of food prevent gestational diabetes during pregnancy?
Research shows eating from 8 or more food groups significantly reduces gestational diabetes risk. A 2026 study of 3,026 pregnant women found those with low dietary diversity had 58% higher risk. Dietary diversity works best combined with healthy weight management.
What food groups should I eat during pregnancy to prevent gestational diabetes?
Aim for variety across 10 groups: grains, vegetables, fruits, legumes, nuts, dairy, eggs, meat, fish, and oils. The research suggests reaching at least 8 different groups daily provides the strongest protection against gestational diabetes.
Does being overweight during pregnancy increase gestational diabetes risk?
Yes. A 2026 study found that being overweight or obese before pregnancy combined with low dietary diversity and excessive weight gain created the highest gestational diabetes risk. Weight management plus dietary diversity offers the best protection.
When should I start eating a diverse diet to prevent gestational diabetes?
Ideally before pregnancy or as early as possible in pregnancy. The study measured diet around 6 months into pregnancy, suggesting eating patterns throughout pregnancy matter for reducing gestational diabetes risk.
Is dietary diversity alone enough to prevent gestational diabetes?
Dietary diversity significantly reduces risk, but works best combined with healthy weight management. The research shows that women with diverse diets who also maintained healthy weight had the lowest gestational diabetes risk.
Want to Apply This Research?
- Track the number of different food groups eaten each day, aiming for at least 8 groups. Log foods in categories: grains, vegetables, fruits, legumes, nuts/seeds, dairy, eggs, meat/poultry, fish, and oils. Count how many categories you hit daily.
- Set a daily goal to eat from 8+ food groups. Use the app to plan meals that include variety—for example, breakfast with whole grain toast (grain) and berries (fruit), lunch with chicken (meat) and broccoli (vegetable), snacks with nuts (legumes/nuts) and yogurt (dairy). The app can suggest recipes that maximize food group diversity.
- Weekly review of food group diversity scores. Track patterns over 4-week periods to identify which food groups you’re missing. Set reminders to include underrepresented groups. For pregnant women, share weekly diversity reports with healthcare providers to demonstrate dietary adherence.
This research provides evidence about dietary patterns and gestational diabetes risk, but should not replace personalized medical advice. Gestational diabetes is a serious pregnancy condition requiring professional medical diagnosis and management. All pregnant women should work with their healthcare provider or registered dietitian for personalized nutrition guidance. This study was conducted in a Chinese population and may not apply equally to all ethnic groups. If you have concerns about gestational diabetes risk, discuss screening and prevention strategies with your obstetrician or midwife.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.