When pregnant people don’t eat enough protein, it can affect their babies’ health in ways that last a lifetime. Scientists reviewed hundreds of studies to understand how low-protein diets during pregnancy impact different body systems—from the brain and heart to metabolism and immunity. The research shows that protein deficiency creates stress on the developing baby, which can leave lasting marks on their genes that influence health problems years or even decades later. This matters because millions of pregnant people worldwide struggle with food insecurity or eat diets lacking proper nutrition.
The Quick Take
- What they studied: How low-protein diets during pregnancy affect babies’ development and health throughout their entire lives
- Who participated: This was a review that analyzed findings from many different studies involving both animal research and human populations affected by malnutrition
- Key finding: Maternal protein restriction causes widespread changes in developing babies’ organs and systems, with effects that can persist into adulthood and old age
- What it means for you: If you’re pregnant or planning to become pregnant, adequate protein intake is crucial for your baby’s long-term health. This is especially important for people facing food insecurity or following restrictive diets. Talk to your healthcare provider about protein needs during pregnancy.
The Research Details
This is a narrative review, meaning scientists read and summarized findings from many different research studies on maternal protein restriction. The review combined information from two main types of research: controlled experiments (mostly in animals) that show exactly how protein deficiency affects development, and real-world studies in human populations experiencing malnutrition. By bringing together evidence from both types of research, the authors could identify patterns in how protein deficiency affects different body systems across the entire lifespan—from before birth through old age.
The researchers focused specifically on protein deficiency rather than general malnutrition because protein plays such a critical role in building and maintaining every cell in the body. They examined studies looking at different stages of development: pregnancy, infancy, childhood, adulthood, and aging. This comprehensive approach helps explain why nutrition during pregnancy matters so much for lifelong health.
Understanding how maternal nutrition affects lifelong health is important because it shifts our thinking about when health problems begin. Instead of thinking diseases only start when we’re adults, this research shows that poor nutrition during pregnancy can set the stage for health problems decades later. This knowledge helps doctors and public health officials prioritize nutrition support for pregnant people, especially those with limited access to food.
This is a review article that summarizes existing research rather than conducting a new study. The strength of this type of work depends on the quality of studies reviewed and how thoroughly the authors searched for relevant research. The review appears comprehensive, drawing from both animal studies (which show cause-and-effect clearly) and human studies (which show real-world effects). However, because it’s a summary of other work rather than original research, it cannot prove causation on its own—it can only show patterns across many studies.
What the Results Show
The review found that maternal protein restriction affects nearly every major body system in developing babies. The brain and nervous system are particularly vulnerable, with protein deficiency potentially affecting learning, memory, and behavior later in life. The heart and blood vessels also show changes, which may increase risk for heart disease in adulthood. Protein deficiency during pregnancy appears to disrupt how the baby’s metabolism develops, potentially increasing the risk of obesity and diabetes later.
One of the most important findings is that these effects aren’t just temporary—they can last throughout the entire lifespan. The research suggests that poor protein nutrition creates a stressful environment for the developing baby, which triggers changes in how genes are expressed (called epigenetic changes). Think of it like the baby’s body learning to survive in a low-nutrient environment, which then causes problems when adequate nutrition becomes available later in life.
The immune system also appears affected, with studies suggesting that protein deficiency during pregnancy may weaken immune function and increase susceptibility to infections and diseases. Additionally, the kidneys, liver, and other organs show structural and functional changes that can have long-term consequences.
The review also found effects on reproductive health, with some studies showing that maternal protein restriction affects fertility and sexual function in offspring. Bone development appears compromised, potentially increasing osteoporosis risk later in life. Muscle development and strength may also be reduced, affecting physical capability in adulthood. Some studies suggest effects on mental health and stress response, with offspring potentially showing increased anxiety or depression.
This research builds on the Developmental Origins of Health and Disease (DOHaD) framework, which has been developing over the past 20+ years. Previous research established that fetal nutrition matters for lifelong health, but this review specifically focuses on protein’s role. The findings align with and expand upon earlier work showing that maternal malnutrition has far-reaching consequences, while adding detail about protein’s specific importance and the mechanisms involved.
As a review article, this work summarizes other studies but doesn’t conduct new research, so it can identify patterns but not prove direct cause-and-effect in humans. Many studies reviewed were conducted in animals, which may not perfectly reflect human biology. The review cannot account for other factors that affect health, like genetics, childhood nutrition, or lifestyle. Additionally, it’s difficult to separate the effects of protein deficiency alone from other nutritional deficiencies that often occur together during malnutrition.
The Bottom Line
Pregnant people should ensure adequate protein intake as recommended by their healthcare provider (typically 70+ grams daily, though individual needs vary). This is a high-confidence recommendation based on extensive research. People planning pregnancy should also prioritize good nutrition before conception. If food insecurity is a concern, connect with local food assistance programs and discuss nutrition with healthcare providers.
This research is most relevant for pregnant people, those planning pregnancy, and people of childbearing age. It’s also important for healthcare providers, public health officials, and policymakers working on maternal health and food security. Parents of young children should understand that early nutrition affects lifelong health. Anyone with a history of maternal malnutrition may want to discuss potential health implications with their doctor.
Some effects of maternal protein deficiency appear immediately (poor fetal growth, low birth weight), while others emerge gradually during childhood (developmental delays, growth problems). Many effects don’t become obvious until adulthood or later life (metabolic disease, heart disease, aging-related problems). This means the importance of maternal nutrition may not be fully apparent for decades.
Want to Apply This Research?
- If pregnant or planning pregnancy, track daily protein intake (target grams per day based on healthcare provider recommendation) and monitor food security status. Log protein sources at each meal to ensure variety and adequacy.
- Set a specific daily protein target with your healthcare provider and use the app to plan meals that meet this goal. Include diverse protein sources (lean meats, fish, eggs, legumes, dairy, nuts) and set reminders for protein-rich snacks. If facing food insecurity, use the app to locate and track local food assistance resources.
- Track protein intake weekly and review trends monthly. For those with food insecurity, monitor access to adequate nutrition and connect with support services. After pregnancy, continue tracking nutrition quality as it affects infant development through breastfeeding. Long-term, monitor child growth and development milestones as indicators of adequate early nutrition.
This review summarizes research on how maternal protein deficiency affects offspring health. It is not medical advice. Pregnant people should work with their healthcare provider to determine appropriate protein intake based on individual needs, health status, and any medical conditions. If you have concerns about nutrition during pregnancy or food insecurity, discuss these with your doctor or a registered dietitian. This information is for educational purposes and should not replace professional medical guidance.