A 2026 cohort study of 8,259 first-time pregnant women found that eating a diet high in fat, sugar, and salt increased pregnancy complications by 1-3 cases per 100 pregnancies. According to Gram Research analysis, eating more vegetables appeared to reduce this risk somewhat, though the protective effect was modest and not statistically certain. The research suggests diet quality matters during pregnancy, but vegetables alone cannot fully offset the harm from unhealthy eating patterns.
A new study of over 8,000 pregnant women found that eating a diet high in fat, sugar, and salt increases the risk of pregnancy problems like gestational diabetes and preeclampsia. However, the research suggests that eating more vegetables might reduce some of these risks. According to Gram Research analysis, about 23% of the women in the study experienced pregnancy complications, and those who ate unhealthy diets were more likely to have problems. The good news is that women who ate more vegetables appeared to have better outcomes, though the protection wasn’t as strong as researchers hoped. This research highlights why what pregnant women eat matters for both their health and their baby’s health.
Key Statistics
A 2026 cohort study of 8,259 pregnant women found that 23% experienced adverse pregnancy outcomes including preeclampsia, gestational diabetes, premature birth, or small babies, with high-fat, high-sugar, high-salt diets associated with 1-3 additional cases per 100 pregnancies.
According to research reviewed by Gram, women eating 1.25 cups of vegetables per 1,000 calories had lower pregnancy complication risk than those eating only 0.5 cups, though the difference was not statistically precise.
A 2026 analysis of 8,259 first-time mothers found that approximately 29% consumed a high-fat, sugar, and sodium diet, which was linked to increased risk of preeclampsia, gestational diabetes, and small-for-gestational-age births.
The Quick Take
- What they studied: Whether eating lots of vegetables and fruit can protect pregnant women from problems caused by eating too much fat, sugar, and salt
- Who participated: 8,259 women who were pregnant for the first time, tracked between 2010 and 2013. Researchers looked at what they ate before and during early pregnancy.
- Key finding: Women eating high-fat, high-sugar, high-salt diets had 1-3 more pregnancy problems per 100 pregnancies compared to women eating healthier diets. Eating more vegetables appeared to reduce this risk somewhat, though the effect wasn’t as strong as expected.
- What it means for you: If you’re planning to get pregnant or are pregnant, eating plenty of vegetables and avoiding processed foods high in fat, sugar, and salt may help reduce your risk of complications. However, this is one study, and more research is needed to confirm how much vegetables can protect you.
The Research Details
Researchers followed 8,259 women who were having their first baby between 2010 and 2013. Before and during early pregnancy, women answered detailed questions about what they ate using a food frequency questionnaire—basically a checklist of common foods. The researchers then looked at whether women who ate diets high in fat, sugar, and salt had more pregnancy problems like gestational diabetes (high blood sugar during pregnancy), preeclampsia (dangerously high blood pressure), premature birth, or babies that were too small.
The clever part of this study was that researchers used advanced computer analysis (machine learning) to see if eating more vegetables and fruit could reduce the harmful effects of the unhealthy diet. This type of analysis is more sophisticated than traditional statistics and can find patterns that might be missed otherwise.
The researchers compared women with different levels of vegetable and fruit intake to see if those eating more produce had better pregnancy outcomes, even if they ate some unhealthy foods.
This research approach matters because pregnancy is a critical time when diet directly affects both the mother and developing baby. By studying real women’s actual eating habits (rather than just giving some women a diet and others a different one), researchers can see what happens in real life. The machine learning approach also helps identify which groups of women benefit most from eating vegetables, which could help doctors give better advice.
This study has several strengths: it included a large number of women (over 8,000), tracked their actual diets carefully, and looked at multiple pregnancy problems rather than just one. However, the study has limitations. The researchers couldn’t prove that diet caused the problems—only that they were associated. Also, women reported their own eating habits, which can be inaccurate. The results about vegetables protecting against problems were not statistically precise, meaning the researchers weren’t completely confident in those specific numbers.
What the Results Show
About 23% of the pregnant women in the study experienced at least one serious pregnancy problem (preeclampsia, gestational diabetes, premature birth, or a baby that was too small). About 29% of women ate a diet high in fat, sugar, and salt. Women eating this unhealthy diet had 1 to 3 extra cases of pregnancy problems per 100 pregnancies compared to women eating other diets.
When researchers looked at whether eating vegetables helped, they found that women eating more vegetables did appear to have somewhat lower risk. For example, women eating 1.25 cups of vegetables per 1,000 calories had a lower risk than women eating only 0.5 cups. However, these numbers weren’t precise enough for researchers to be completely confident.
Interestingly, eating more fruit didn’t seem to reduce the risk as much as eating vegetables did. When women ate both more vegetables and more fruit, there was slightly more protection, but again, the numbers weren’t precise enough to be certain.
When researchers looked at individual pregnancy problems separately, the pattern changed. For preterm birth (babies born too early), eating a high-fat, high-sugar, high-salt diet didn’t seem to increase the risk as much as it did for other problems. This suggests that different pregnancy complications may be affected differently by diet. The protective effect of vegetables also varied depending on which specific pregnancy problem was being studied.
Previous research has shown that diet quality matters during pregnancy, and that both high-fat, high-sugar diets and low vegetable intake are linked to pregnancy problems. This study adds to that knowledge by trying to see if vegetables can protect against the harmful effects of unhealthy eating. However, the results are less clear than many researchers hoped, suggesting the relationship between diet and pregnancy health is more complicated than a simple ‘bad diet + vegetables = protection’ formula.
The biggest limitation is that the results about vegetables protecting against problems weren’t statistically precise—the confidence intervals were wide, meaning the true effect could be much smaller or larger than the numbers suggest. Women reported their own diets, which can be inaccurate or incomplete. The study only included women having their first baby, so results might not apply to women who’ve been pregnant before. Also, the researchers couldn’t prove that the unhealthy diet caused the problems, only that they were associated. Finally, many other factors affect pregnancy health (exercise, stress, genetics, medical conditions), and this study couldn’t account for all of them.
The Bottom Line
If you’re planning pregnancy or are pregnant: eat plenty of vegetables (aim for at least 1 cup per 1,000 calories), limit processed foods high in fat, sugar, and salt, and eat a balanced diet with fruits, whole grains, and lean proteins. These recommendations are supported by this research and many other studies, though this particular study shows the protective effect of vegetables is modest. Confidence level: Moderate—this is one study with imprecise results, but it aligns with broader nutrition science.
This research is most relevant to women who are pregnant or planning to become pregnant, especially those who tend to eat processed foods high in fat, sugar, and salt. Healthcare providers should consider this when counseling pregnant patients about diet. The findings are less relevant to women who already eat a healthy diet with plenty of vegetables. Men and non-pregnant people should not apply these specific findings, though healthy eating benefits everyone.
Diet changes during pregnancy can affect pregnancy outcomes throughout the pregnancy, but the most critical time is the first few months when the baby’s organs are forming. If you’re planning pregnancy, starting to eat better 2-3 months before trying to conceive may be most beneficial. If you’re already pregnant, improving your diet now can still help, though earlier changes are generally better.
Frequently Asked Questions
Can eating vegetables prevent pregnancy complications from a bad diet?
Vegetables may reduce some risk, but they cannot fully prevent complications from unhealthy eating. A 2026 study of 8,259 pregnant women found vegetables provided modest protection, but eating a healthy overall diet is more important than relying on vegetables to offset junk food.
How much vegetables should I eat during pregnancy?
Research suggests aiming for at least 1-1.25 cups of vegetables per 1,000 calories consumed daily. This typically means 2.5-3 cups of vegetables per day for most pregnant women, spread across meals for best nutrition and blood sugar control.
Does fruit protect pregnancy health as much as vegetables?
According to a 2026 study of over 8,000 pregnant women, vegetables appeared more protective than fruit alone against pregnancy complications from unhealthy diets. However, eating both vegetables and fruit together is ideal for overall nutrition and health.
What pregnancy problems are most linked to poor diet?
A 2026 study found high-fat, high-sugar, high-salt diets were most strongly linked to preeclampsia, gestational diabetes, and small babies. Premature birth showed less association with diet in this research, suggesting different complications have different dietary risk factors.
When should I start eating better if I want to get pregnant?
Starting 2-3 months before trying to conceive is ideal, as this covers the critical early pregnancy period when organs form. However, improving diet at any point during pregnancy can still provide benefits for both mother and baby health.
Want to Apply This Research?
- Track daily vegetable intake in cups or servings, aiming for at least 2.5-3 cups per day. Log specific vegetables eaten (broccoli, spinach, carrots, peppers) to ensure variety and nutrient density. Monitor weekly totals to identify patterns.
- Set a daily reminder to add one vegetable to each meal. Start by adding vegetables to breakfast (spinach in eggs), lunch (salad or veggie side), and dinner (roasted vegetables). Use the app to find quick vegetable recipes and set shopping reminders for fresh produce.
- Weekly review of vegetable intake trends. Track any pregnancy-related symptoms or health markers (blood pressure, weight gain) alongside diet logs to see personal patterns. Share monthly summaries with healthcare provider to discuss diet quality and pregnancy health.
This research summary is for educational purposes only and should not replace medical advice from your healthcare provider. Pregnancy is a unique medical condition, and dietary needs vary by individual. If you are pregnant or planning pregnancy, consult with your obstetrician, midwife, or registered dietitian before making significant dietary changes. This study shows associations between diet and pregnancy outcomes but does not prove that diet alone causes these outcomes. Individual results vary based on genetics, medical history, and other health factors not measured in this study.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
