Research shows that pregnant women who eat more animal-based proteins and animal fats have about 60% higher risk of developing gestational diabetes, while those eating more fiber have about 35% lower risk, according to a 2026 systematic review of 25 studies involving 115,496 women. Gram Research analysis indicates that focusing on plant-based foods, whole grains, and vegetables while limiting red meat and fatty animal products during pregnancy may help reduce diabetes risk.
A major review of 25 studies involving over 115,000 pregnant women reveals that what mothers eat before and during pregnancy significantly impacts their risk of developing gestational diabetes—a type of diabetes that occurs during pregnancy. According to Gram Research analysis, eating more animal-based proteins and animal fats increases diabetes risk, while eating more fiber protects against it. The findings suggest that pregnant women should focus on plant-based foods and high-fiber options while limiting red meat and fatty animal products, though researchers emphasize that more studies are needed to fully understand how protein intake affects pregnancy health.
Key Statistics
A 2026 systematic review of 25 prospective studies involving 115,496 pregnant women found that higher animal-sourced protein intake was associated with a 62% increased risk of gestational diabetes compared to lower intake.
According to the same 2026 meta-analysis of 115,496 pregnant women, dietary fiber intake showed a protective effect, with higher fiber consumption associated with 35% lower risk of gestational diabetes in a dose-response pattern.
A 2026 review analyzing 25 studies found that animal-sourced fat intake was associated with 59% higher gestational diabetes risk at higher consumption levels compared to lower levels.
The 2026 systematic review of 115,496 pregnant women across 25 studies showed that vegetable-based fat intake increased gestational diabetes risk by 25%, though this effect was smaller than animal fat sources.
The Quick Take
- What they studied: How different types of food—proteins, fats, carbohydrates, and fiber—eaten before or during pregnancy affect a woman’s chances of developing gestational diabetes (a temporary form of diabetes that happens during pregnancy).
- Who participated: Over 115,000 pregnant women across 25 different research studies from around the world. Researchers looked at what these women ate and tracked whether they developed gestational diabetes.
- Key finding: Women who ate more animal-based protein and animal fat had about 60% higher risk of gestational diabetes, while women who ate more fiber had about 35% lower risk. These patterns held true even when researchers looked at different amounts of food intake.
- What it means for you: If you’re planning to get pregnant or are currently pregnant, eating more plant-based foods, whole grains, and vegetables while limiting red meat and fatty animal products may help reduce your diabetes risk. However, talk to your doctor before making major diet changes, as individual needs vary.
The Research Details
Researchers conducted a systematic review, which means they searched through thousands of published studies to find the highest-quality evidence on this topic. They identified 25 prospective observational studies—studies that followed pregnant women over time and recorded what they ate and whether they developed gestational diabetes. This type of study is valuable because it tracks real-world eating patterns and health outcomes rather than testing a specific intervention.
The researchers used strict criteria to evaluate study quality, checking for potential biases and problems that might affect the results. They then combined the data from all 25 studies using a statistical method called meta-analysis, which allows researchers to see patterns across many studies. They looked at how different amounts of various foods affected diabetes risk, not just whether people ate them or not.
The team also rated the certainty of their evidence using a system called GRADE, which helps readers understand how confident they should be in the findings. This approach ensures that the conclusions are based on the strongest available evidence.
This research approach is important because gestational diabetes affects many pregnant women and increases their risk of developing type-2 diabetes later in life. By looking at multiple high-quality studies together, researchers can identify patterns that might not be obvious in a single study. Understanding which specific foods increase or decrease risk helps doctors and pregnant women make better dietary choices. The systematic review approach also helps separate reliable findings from one-time results that might not be real.
This study has several strengths: it included a large number of women (over 115,000), used multiple databases to find studies, had at least two reviewers check the quality of each study, and used established methods to rate evidence certainty. However, all the included studies were observational, meaning researchers watched what people ate rather than assigning them to eat specific diets. This type of study can show associations but cannot prove that food directly causes gestational diabetes. Additionally, the studies varied in how they measured food intake and defined gestational diabetes, which added some uncertainty to the results.
What the Results Show
The research found clear patterns in how different foods affect gestational diabetes risk. Animal-sourced protein (like meat, poultry, and fish) showed the strongest link to increased risk—women eating the most had about 62% higher risk compared to those eating the least. Animal-sourced fats (like butter and fatty meats) showed a similar pattern, with about 59% higher risk at higher intake levels. Both of these associations appeared to follow a dose-response pattern, meaning that as women ate more of these foods, their risk increased gradually.
Total protein intake (combining both animal and plant sources) also increased risk by about 63%, though this pattern didn’t show a clear dose-response relationship. Vegetable-based fats showed a smaller but still meaningful increase in risk of about 25%.
The most protective finding involved dietary fiber. Women eating the most fiber had about 35% lower risk of gestational diabetes compared to those eating the least, and this protective effect increased with higher fiber intake. Fiber from whole grains, vegetables, and fruits appeared to be genuinely protective.
These findings align with general healthy eating advice for all people, but they highlight that pregnant women may need to pay special attention to protein sources and animal fat intake, which isn’t currently emphasized in most pregnancy dietary guidelines.
The researchers noted significant variation in how different studies measured these associations, particularly for protein intake. Some studies showed stronger effects than others, suggesting that individual factors like genetics, overall diet quality, and lifestyle may influence how macronutrients affect diabetes risk. The analysis also revealed that the type of carbohydrate (refined versus whole grain) may matter, though the evidence was less clear than for protein and fat.
This is the first comprehensive review to examine all major macronutrients together in relation to gestational diabetes. Previous studies had looked at individual nutrients or foods in isolation. The findings largely confirm what nutritionists have recommended for general health—eating more fiber and less animal fat—but add new concern about protein intake during pregnancy, which hasn’t been a major focus of pregnancy dietary guidelines. The results align with research on type-2 diabetes prevention in non-pregnant populations, suggesting that similar dietary principles may apply during pregnancy.
The main limitation is that all included studies were observational, meaning researchers couldn’t prove that these foods directly cause gestational diabetes—only that they’re associated with it. Women who eat more animal protein might differ in other ways (exercise, overall health, genetics) that also affect diabetes risk. Additionally, the studies measured food intake differently, and some relied on women remembering what they ate months or years earlier, which can be inaccurate. The researchers also noted high variation in results across studies for some nutrients, suggesting that factors not measured in the analysis might influence the findings. Finally, most studies were conducted in developed countries, so results may not apply equally to all populations worldwide.
The Bottom Line
For women planning pregnancy or currently pregnant: increase fiber intake through whole grains, vegetables, legumes, and fruits (high confidence); reduce intake of red meat and fatty animal products (moderate-to-high confidence); consider plant-based protein sources more often than animal sources (moderate confidence). These changes align with general healthy eating advice and may specifically reduce gestational diabetes risk. Discuss any major dietary changes with your healthcare provider, as individual nutritional needs vary during pregnancy.
This research is most relevant for women who are pregnant or planning to become pregnant, particularly those with risk factors for gestational diabetes (family history of diabetes, overweight, previous gestational diabetes, or certain ethnic backgrounds). Healthcare providers, including obstetricians and registered dietitians, should consider these findings when counseling pregnant patients. Women without pregnancy plans can also benefit from these dietary patterns for general health. This research is less directly applicable to men or non-pregnant women, though the general principles align with healthy eating for everyone.
Dietary changes typically take several weeks to show metabolic effects. For gestational diabetes specifically, the critical period appears to be before pregnancy and early pregnancy, so ideally women should adopt these eating patterns before conception. If already pregnant, making these changes as soon as possible may still provide benefit, though the protective effect of dietary fiber appears to build over time. Most women would see stable eating patterns within 2-4 weeks of making dietary changes.
Frequently Asked Questions
Can diet really prevent gestational diabetes during pregnancy?
Diet appears to play a significant role. Research shows women eating more fiber and less animal fat have substantially lower gestational diabetes risk. However, diet is one factor among many—genetics, weight, and age also matter. Talk to your doctor about your individual risk factors and dietary needs.
Should pregnant women avoid eating meat and protein?
Not completely, but the type matters. The research suggests limiting red meat and fatty animal products while choosing leaner sources and plant-based proteins like beans, lentils, and nuts. Protein is essential during pregnancy—focus on healthier sources rather than avoiding it entirely.
How much fiber should I eat during pregnancy to reduce diabetes risk?
General recommendations suggest 25-30 grams of fiber daily for women. The research shows protective effects increase with higher fiber intake. Sources include whole grains, vegetables, fruits, beans, and legumes. Increase fiber gradually and drink plenty of water to avoid digestive discomfort.
Is gestational diabetes permanent or does it go away after pregnancy?
Gestational diabetes typically resolves after pregnancy, but women who develop it have significantly higher risk of developing type-2 diabetes later in life. This is why dietary changes during pregnancy are important—they may prevent both gestational diabetes and future diabetes risk.
Can I make these dietary changes if I’m already pregnant?
Yes. While ideally these changes begin before pregnancy, adopting healthier eating patterns at any point during pregnancy may still provide benefit. Consult your healthcare provider before making significant dietary changes to ensure they meet your individual nutritional needs during pregnancy.
Want to Apply This Research?
- Track daily fiber intake (target: 25-30 grams for women) and weekly servings of red meat and processed meat (target: limit to 1-2 servings per week). Log these alongside blood sugar readings if monitoring gestational diabetes.
- Replace one animal protein source per day with a plant-based option (beans, lentils, tofu, nuts). Add one high-fiber food to each meal (whole grain bread, vegetables, berries). Track these swaps in the app to build consistency.
- Weekly review of fiber intake trends and animal protein consumption. Monthly check-ins with healthcare provider on blood sugar levels and dietary adherence. Use app notifications to remind users of fiber-rich snack options and to log meals, creating accountability for dietary changes throughout pregnancy.
This article summarizes research findings and is not medical advice. Gestational diabetes is a serious pregnancy condition requiring professional medical care. If you are pregnant or planning pregnancy, consult with your obstetrician or registered dietitian before making significant dietary changes. Individual nutritional needs vary based on personal health status, medical history, and pregnancy-specific factors. This research shows associations between diet and gestational diabetes risk but does not prove that dietary changes alone will prevent the condition. Always follow your healthcare provider’s recommendations for pregnancy nutrition and diabetes screening.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.