According to Gram Research analysis, pregnant women with gestational diabetes who eat ultra-processed foods face a 74% higher risk of needing a cesarean section, with the risk jumping to 413% higher for overweight women. The study of 279 Chinese women found that junk food consumption also disrupted overall diet quality, reducing intake of vegetables and dairy products essential for healthy pregnancy outcomes.
A new study of nearly 280 pregnant women with gestational diabetes found that eating ultra-processed foods—like packaged snacks, fast food, and sugary drinks—significantly increased their chances of needing a cesarean section. Women who ate the most junk food were 74% more likely to have a C-section, and the risk jumped even higher for women who were overweight before pregnancy. The research also showed that women eating lots of processed foods weren’t getting enough vegetables and dairy products, which are important during pregnancy. Interestingly, the junk food didn’t directly affect blood sugar control, but it still posed real risks for how babies were delivered.
Key Statistics
A 2026 cohort study of 279 pregnant women with gestational diabetes found that ultra-processed food exposure increased cesarean section risk by 74% compared to women with minimal junk food intake.
Among overweight or obese women with gestational diabetes, ultra-processed food consumption increased cesarean section risk by 413%, according to a 2026 Chinese study of 279 pregnancies.
Women with gestational diabetes who consumed ultra-processed foods showed significantly lower vegetable intake (p<0.001) and dairy consumption (p=0.007) compared to those avoiding processed foods, per a 2026 cohort analysis of 279 pregnancies.
A 2026 study of 279 pregnant women with gestational diabetes found that ultra-processed food exposure did not significantly affect blood glucose control, suggesting junk food impacts pregnancy outcomes through mechanisms beyond blood sugar regulation.
The Quick Take
- What they studied: Whether eating ultra-processed foods (junk food) during pregnancy affects the need for C-sections and baby weight in women with gestational diabetes
- Who participated: 279 pregnant women in China who had been diagnosed with gestational diabetes (a type of diabetes that develops during pregnancy)
- Key finding: Women who ate the most ultra-processed foods were 74% more likely to need a cesarean section compared to women who ate little to no junk food. For overweight women, the risk was even higher—413% more likely
- What it means for you: If you’re pregnant with gestational diabetes, limiting ultra-processed foods and eating more vegetables and dairy may help reduce your chances of needing a C-section. However, this is one study, and you should always follow your doctor’s specific dietary recommendations
The Research Details
Researchers looked back at the medical records and dietary information of 279 women in China who had gestational diabetes during their pregnancies. They calculated how much ultra-processed food each woman ate and used a special scoring system called the Diet Balance Index for Pregnancy to measure the overall quality of their diets. They then compared outcomes like delivery method (vaginal or C-section) and baby weight between women who ate lots of junk food and those who ate very little.
The study collected detailed information about what each woman ate during her pregnancy and looked at her medical records to see what happened during delivery and with the baby’s health. The researchers used statistical methods to figure out whether the junk food was actually causing the higher C-section rates, or if other factors like a woman’s weight before pregnancy were responsible.
This research approach is important because it looks at real-world pregnancy outcomes rather than just lab measurements. By studying women who already had gestational diabetes, the researchers could see how food choices affected actual delivery outcomes. The study also measured diet quality in a comprehensive way, looking at whether women were getting enough of the healthy foods they need, not just counting calories
This was a retrospective cohort study, which means researchers looked back at existing medical records rather than following women forward in time. This type of study is good for finding associations but can’t prove that junk food directly causes C-sections. The study was conducted in China with Chinese women, so results may not apply equally to all populations. The researchers adjusted their analysis for several important factors like pre-pregnancy weight and age, which strengthens the findings. However, the study didn’t measure all possible factors that could influence C-section rates
What the Results Show
Women who ate ultra-processed foods had a 74% higher risk of needing a cesarean section compared to women who didn’t eat these foods. This increased risk remained even after researchers accounted for other important factors like age and pre-pregnancy weight.
The risk was even more dramatic for women who were overweight or obese before pregnancy. These women who also ate lots of ultra-processed foods had a 413% higher risk of C-section—meaning they were more than 4 times as likely to need the surgery.
Women eating the most junk food also had significantly worse overall diet quality. They weren’t eating enough vegetables or dairy products, which are important sources of nutrients during pregnancy. Interestingly, they were also eating less plant-based oils, which are healthy fats.
One surprising finding: ultra-processed food consumption didn’t directly affect blood sugar control during pregnancy, as measured by glucose tolerance tests. This suggests the junk food’s impact on C-section risk works through a different mechanism than just affecting blood sugar
The study found widespread nutritional imbalances in all the pregnant women with gestational diabetes, but these problems were worse in women eating lots of ultra-processed foods. The inadequate intake of vegetables and dairy products is concerning because these foods provide essential nutrients for both mother and baby. The lower intake of plant oils among the ultra-processed food group is notable because healthy fats are important for fetal development
Previous research has shown that ultra-processed foods are linked to various pregnancy complications and poor health outcomes. This study adds new evidence that junk food specifically increases C-section risk in women with gestational diabetes. The finding that diet quality matters independently of blood sugar control aligns with growing research showing that food quality affects pregnancy outcomes through multiple pathways, not just glucose metabolism. However, most previous studies on this topic have been conducted in Western populations, so this Chinese study provides important evidence for Asian populations
This study looked backward at existing records rather than following women forward, which makes it harder to prove cause-and-effect. The researchers couldn’t measure all possible factors that might influence C-section decisions, such as specific medical complications or doctor preferences. The study was conducted only in China with Chinese women, so the results may not apply equally to other populations with different genetics, food availability, or healthcare practices. The study didn’t measure exactly how much ultra-processed food women ate in precise amounts, only whether they ate it or not. Additionally, the study couldn’t determine whether women changed their diets after being diagnosed with gestational diabetes, which could affect the results
The Bottom Line
If you have gestational diabetes, limiting ultra-processed foods and focusing on whole foods—especially vegetables, dairy products, and healthy oils—may help reduce your C-section risk. This recommendation has moderate confidence based on this single study. Always work with your healthcare provider or a dietitian who specializes in pregnancy to create a personalized eating plan. Don’t make major dietary changes without medical guidance
This research is most relevant to pregnant women with gestational diabetes, particularly those who are overweight or obese. Healthcare providers caring for pregnant women with gestational diabetes should consider discussing ultra-processed food intake with their patients. Women planning pregnancy who have risk factors for gestational diabetes may also benefit from reducing junk food intake. The findings are less directly applicable to pregnant women without gestational diabetes, though the general principle of eating whole foods is still important
Changes in diet quality may take several weeks to show effects on pregnancy outcomes. If you’re already pregnant with gestational diabetes, it’s important to make dietary changes as soon as possible, ideally under guidance from your healthcare team. The benefits of improved diet quality accumulate throughout pregnancy, so earlier changes are better than waiting until late pregnancy
Frequently Asked Questions
Does eating junk food during pregnancy with gestational diabetes affect blood sugar levels?
Surprisingly, a 2026 study of 279 women found that ultra-processed food consumption didn’t directly affect blood glucose test results. However, junk food still increased C-section risk by 74%, suggesting it harms pregnancy through other pathways beyond blood sugar control.
How much does ultra-processed food increase C-section risk in overweight pregnant women with gestational diabetes?
A 2026 study found overweight women with gestational diabetes who consumed ultra-processed foods faced a 413% higher C-section risk—more than 4 times as likely—compared to those avoiding junk food.
What specific foods should pregnant women with gestational diabetes avoid?
Research shows ultra-processed foods like packaged snacks, fast food, and sugary drinks increase C-section risk. Focus instead on whole foods: fresh vegetables, dairy products, whole grains, and healthy oils, ideally with guidance from your healthcare provider.
Can changing my diet during pregnancy reduce C-section risk if I have gestational diabetes?
A 2026 study suggests limiting ultra-processed foods and eating more vegetables and dairy may reduce C-section risk, though individual results vary. Work with your doctor or dietitian to create a personalized plan, as dietary changes work best when medically supervised.
Why do women with gestational diabetes who eat junk food need more C-sections?
A 2026 study found ultra-processed food doesn’t directly affect blood sugar but still increases C-section risk by 74%. The mechanism likely involves poor overall nutrition, inflammation, or other factors beyond glucose control that affect pregnancy outcomes.
Want to Apply This Research?
- Track daily ultra-processed food servings and compare to servings of vegetables and dairy products. Set a goal to reduce ultra-processed foods to fewer than 2 servings per day while increasing vegetables to at least 3 servings and dairy to at least 2 servings daily
- Replace one ultra-processed food item per day with a whole food alternative. For example, swap packaged snacks for fresh fruit, replace sugary drinks with water or unsweetened tea, or choose whole grain bread instead of processed white bread
- Weekly review of food diary to identify patterns in ultra-processed food consumption. Track which whole foods are easiest to substitute and which are most challenging. Monitor how dietary changes affect energy levels and blood sugar readings if you’re testing at home
This article summarizes research findings and is not medical advice. Gestational diabetes requires individualized medical care from your healthcare provider. Do not make significant dietary changes during pregnancy without consulting your doctor or a registered dietitian specializing in pregnancy nutrition. Blood sugar management and delivery method decisions should always be made in consultation with your healthcare team based on your specific medical situation. This study was conducted in a Chinese population; results may not apply equally to all groups. Always follow your healthcare provider’s specific recommendations for managing gestational diabetes.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.