According to Gram Research analysis, a mother’s high-fat diet during pregnancy may influence how her grown sons prefer fatty foods and how their brains respond to rewards, while daughters show different patterns. In a controlled animal study, male offspring of mothers fed a high-fat diet showed increased preference for fatty foods and decreased dopamine gene expression in the brain’s reward system. The diabetes medication metformin altered these preferences differently in males versus females, suggesting that prenatal nutrition and medication exposure have sex-specific, lasting effects on food preferences and brain development.
A new study shows that what a pregnant rat mother ate and whether she took the diabetes drug metformin can influence how her grown offspring respond to fatty and sugary foods. Researchers found these effects work differently in males and females, and they involve changes in brain genes related to reward and pleasure. The study suggests that a mother’s diet and certain medications during pregnancy may have lasting effects on how her children’s brains respond to tempting foods, potentially influencing eating habits later in life.
Key Statistics
In a 2026 animal study published in Physiology and Behavior, male offspring of mothers fed a high-fat diet showed increased preference for fatty foods and decreased dopamine-related gene expression in the brain’s reward system compared to offspring of mothers on a normal diet.
A 2026 study found that metformin treatment during pregnancy decreased low-concentration sucrose preference in male offspring and reduced opioid-related gene expression in the reward system, with these changes persisting into adulthood in males but not females.
Research from 2026 showed that maternal high-fat diet elevated sweet taste perception gene expression in male offspring’s taste buds, while metformin treatment reversed these changes, demonstrating that prenatal medication can counteract dietary effects on taste sensitivity.
The Quick Take
- What they studied: Whether a pregnant mother’s high-fat diet and a diabetes medication called metformin change how her grown children prefer fatty and sugary foods, and what brain changes might explain these preferences.
- Who participated: Sprague-Dawley rats (a common laboratory rat breed) and their offspring. Some pregnant mothers ate a normal diet, some ate a high-fat diet, and some ate a high-fat diet while taking metformin.
- Key finding: In male offspring, mothers who ate a high-fat diet produced sons who preferred fatty foods more and had lower levels of dopamine-related genes in their brains. Metformin treatment changed how offspring responded to sugary foods and altered reward-related genes, but these effects differed between males and females.
- What it means for you: This research suggests that a mother’s diet during pregnancy may influence her children’s food preferences and how their brains respond to tempting foods. However, this is animal research, so we cannot yet say these exact effects happen in humans. The findings highlight why maternal nutrition during pregnancy matters for long-term health.
The Research Details
Researchers used laboratory rats to study how maternal diet affects offspring. They divided pregnant rat mothers into three groups: one eating a normal diet, one eating a high-fat diet, and one eating a high-fat diet while receiving metformin, a medication commonly used to treat type 2 diabetes. After the babies were born and grew into adults, the researchers tested how much the offspring preferred fatty foods and sugary drinks. They also examined the offspring’s brain tissue and taste buds to measure the activity of specific genes related to reward, pleasure, and sweet taste perception. The researchers compared results between male and female offspring to see if sex made a difference.
This research approach is important because it allows scientists to study cause and effect in a controlled way that would be impossible in humans. By measuring specific genes in the brain and taste system, researchers can understand the biological mechanisms, or the ‘how and why,’ behind food preferences. Testing both males and females separately reveals that pregnancy effects are not the same for everyone, which is crucial information for understanding human health.
This is a controlled laboratory study using a well-established animal model, which allows for precise measurement of genes and careful control of diet. However, animal studies do not always translate directly to humans. The study was published in a peer-reviewed journal, meaning other scientists reviewed the work before publication. The specific sample sizes for each group were not provided in the abstract, which limits our ability to assess statistical power. Readers should view this as preliminary evidence that suggests directions for future human research rather than definitive proof about human behavior.
What the Results Show
In male offspring, maternal high-fat diet increased preference for fatty foods and decreased dopamine-related gene expression in the brain’s reward system. This suggests that exposure to a high-fat diet before birth may rewire how a male offspring’s brain processes food rewards. Metformin treatment in pregnant mothers reduced their sons’ preference for low-concentration sugar solutions and decreased opioid-related genes in the reward system, indicating the medication altered how the brain responds to sweet tastes. Importantly, these changes in reward-related genes persisted from early life into adulthood in males, suggesting lasting effects. In female offspring, maternal high-fat diet did not increase preference for fatty foods, but it did decrease preference for low-concentration sugar and reduced sweet taste perception genes in the taste buds. Metformin did not reverse these changes in females, and the early-life gene changes did not persist into adulthood in females the way they did in males.
The study found that maternal high-fat diet increased the activity of sweet taste perception genes in the taste buds of male offspring, making them more sensitive to sweetness. Metformin reversed this effect in males but not in females. At weaning (early life), metformin generally decreased dopamine and opioid-related genes in both sexes, but this suppression continued into adulthood only in males. This sex difference suggests that males and females respond differently to the same prenatal conditions, possibly due to biological differences in how their brains develop.
Previous research has shown that maternal diet during pregnancy can influence offspring metabolism and weight gain. This study extends that knowledge by examining specific brain mechanisms related to food reward and preference. The finding that metformin improves metabolic health in offspring (from prior studies) is now paired with evidence that it also changes how the brain responds to food, suggesting multiple pathways through which prenatal conditions affect lifelong health. The sex-specific differences align with growing evidence that males and females experience different developmental trajectories and may respond differently to the same prenatal exposures.
This study used laboratory rats, not humans, so results may not directly apply to people. The abstract does not specify the exact number of animals in each group, making it difficult to assess whether the study had enough subjects to detect real effects. The study measured gene expression at one point in time, so we cannot determine whether these changes are temporary or truly permanent. The research focused on preference and brain genes but did not measure actual eating behavior or long-term health outcomes like weight or disease risk. Additionally, the study did not examine whether other factors, such as exercise or stress, might influence the results.
The Bottom Line
Based on this animal research, the findings suggest that maintaining a healthy diet during pregnancy may be important for shaping offspring’s long-term food preferences and brain development. However, this is preliminary evidence from rats, and we cannot yet make specific recommendations for humans. Pregnant individuals should follow established guidelines for healthy nutrition and consult with healthcare providers about medication use during pregnancy. The research does not suggest that metformin use during pregnancy is harmful; rather, it shows that this medication has effects on the developing brain that warrant further study in humans.
This research is most relevant to pregnant individuals, healthcare providers who advise pregnant patients, and scientists studying how early-life nutrition affects lifelong health. Parents interested in understanding how prenatal factors influence their children’s eating habits may find this informative. Researchers studying obesity, food addiction, and metabolic disease should consider these findings. People taking metformin should not change their medication based on this animal study; they should discuss any concerns with their doctor.
In this rat study, changes in gene expression were observed in adult offspring, suggesting effects persist from pregnancy through adulthood. In humans, we would expect similar long-term effects, but the timeline for seeing behavioral changes in food preferences would likely extend from childhood through adulthood. Any changes in eating habits or health outcomes would probably develop gradually over years rather than appearing immediately.
Frequently Asked Questions
Can what a pregnant mother eats affect her child’s food preferences later in life?
Animal research suggests yes. A 2026 study found that mothers eating a high-fat diet produced sons who preferred fatty foods more as adults and had altered reward-related genes in their brains. However, this is animal research, and human studies are needed to confirm these effects.
Does metformin during pregnancy affect a baby’s developing brain?
According to 2026 research, metformin altered how offspring responded to sugary foods and changed reward-related gene expression in the brain. Effects differed between males and females. Pregnant individuals taking metformin should discuss any concerns with their healthcare provider rather than stopping medication.
Why do males and females respond differently to maternal diet during pregnancy?
The 2026 study found that gene expression changes from maternal high-fat diet persisted into adulthood in males but not females, suggesting biological sex differences in how prenatal nutrition affects brain development. The exact reasons require further research.
Should pregnant women avoid high-fat diets based on this research?
This animal study suggests maternal diet influences offspring’s long-term food preferences and brain development, supporting the importance of healthy pregnancy nutrition. Pregnant individuals should follow established dietary guidelines and consult healthcare providers for personalized nutrition advice.
Can this rat study tell us what will happen in human babies?
Animal studies provide valuable clues about biological mechanisms but do not always translate directly to humans. This research suggests directions for future human studies but should not be interpreted as definitive proof of human effects. More research is needed.
Want to Apply This Research?
- Users interested in this research could track their own food preferences and cravings weekly, noting how often they choose high-fat or high-sugar foods versus healthier options. They could also note energy levels and mood to see if patterns emerge. This personal data could help users understand their own eating triggers and preferences.
- Users could use the app to set goals around reducing high-fat and high-sugar food intake, with reminders and tracking to monitor progress. For pregnant users or those planning pregnancy, the app could provide evidence-based nutrition guidance and track adherence to healthy eating patterns during this critical window.
- Over months and years, users could track whether their food preferences shift as they make dietary changes. Parents could also use the app to monitor their children’s developing food preferences and correlate these with family dietary patterns, helping identify whether early nutrition influences later eating habits.
This article summarizes animal research and should not be interpreted as medical advice for humans. The study was conducted in laboratory rats, and findings may not directly apply to human pregnancy or child development. Pregnant individuals should not make changes to their diet or medications based on this research without consulting their healthcare provider. This research is preliminary and represents one study; it should be considered alongside other evidence and professional medical guidance. If you are pregnant or planning pregnancy, discuss nutrition and medication use with your obstetrician or healthcare provider.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.