Ultra Processed Food and Pregnancy: What the Research Says
An evidence-based summary of current research on ultra-processed food consumption during pregnancy. What studies have found, what they have not proven, and how expectant parents can make informed choices.
Important Medical Disclaimer
This guide is for educational purposes only and is not prenatal nutrition advice. Pregnancy nutrition is highly individualized and depends on factors including pre-existing conditions, medications, gestational age, and personal health history. The research cited is primarily observational and does not establish causation. Always follow the guidance of your OB/GYN, midwife, or registered dietitian for prenatal nutrition recommendations. Do not make significant dietary changes during pregnancy without consulting your healthcare provider.
Why Researchers Are Studying UPF and Pregnancy
Prenatal nutrition has been a medical priority for decades. Guidelines on folic acid, iron, calcium, and omega-3 intake during pregnancy are well established and widely followed. More recently, researchers have begun asking a different question: beyond individual nutrients, does the degree of food processing itself matter during pregnancy?
This is a relatively new area of investigation. The concept of ultra-processed food was formalized through the NOVA classification system in 2009, and pregnancy-specific research using NOVA categories has only emerged in the past few years. The studies that exist are observational -- they track what pregnant people eat and correlate that with pregnancy outcomes. They have identified some associations worth understanding, but they have not proven that ultra-processed food causes any specific pregnancy complication.
This guide summarizes what current research has found, highlights the significant limitations of that research, and discusses practical considerations for expectant parents. It is designed to inform, not to prescribe. The appropriate source for prenatal dietary guidance is your individual healthcare provider, who understands your specific medical history and pregnancy.
What this guide is not: This guide is not a list of foods to avoid during pregnancy. It is not a replacement for prenatal nutrition counseling. It does not make recommendations about what you should or should not eat. It is a summary of published research with its limitations clearly stated. For a broader overview of the UPF research landscape, see our UPF and health effects guide.
What Current Research Shows
A small but growing number of studies have examined associations between ultra-processed food consumption during pregnancy and various gestational outcomes. The findings are summarized below with their key limitations. It is essential to understand that all of these are observational associations, not proven causal relationships.
Gestational Diabetes
Study: A 2022 study published in Environmental Health Perspectives examined dietary patterns among pregnant participants and found that higher UPF consumption during pregnancy was associated with increased risk of gestational diabetes mellitus (GDM).
Gestational diabetes affects approximately 2-10% of pregnancies in the United States. The observed association between UPF intake and GDM risk is consistent with broader research linking UPF consumption to type 2 diabetes in the general population. However, this study could not determine whether ultra-processing itself, the nutrient profile of UPFs (higher sugar, lower fiber), or confounding lifestyle factors explained the association.
Gestational Weight Gain
Study: Research published in JAMA Network Open (2022) found that higher ultra-processed food intake during pregnancy was associated with excessive gestational weight gain, defined as weight gain above the Institute of Medicine guidelines for the participant's pre-pregnancy BMI category.
This finding aligns with the 2019 NIH feeding trial by Kevin Hall, which demonstrated that ultra-processed diets led to higher calorie consumption in a controlled setting. Excessive gestational weight gain is associated with higher rates of cesarean delivery, macrosomia (large birth weight), and postpartum weight retention. However, the pregnancy study was observational and could not control for all variables affecting weight gain during pregnancy, including physical activity, stress, and metabolic differences.
Birth Weight Outcomes
Study: A 2023 systematic review published in Nutrients examined associations between maternal UPF consumption and birth weight outcomes across multiple studies. The results were mixed -- some studies found associations with higher birth weight, others found no significant relationship.
The inconsistency of findings across studies is itself an important data point. It may reflect differences in study populations, dietary assessment methods, or the specific types of UPFs consumed. It also highlights that the relationship between maternal diet and birth weight is complex and influenced by many factors beyond food processing level, including genetics, gestational age at delivery, and maternal health conditions.
Preeclampsia
Evidence status: Preliminary. A small number of studies have examined possible associations between UPF intake during pregnancy and preeclampsia risk. Some have reported suggestive associations, but the evidence is limited and inconsistent.
Preeclampsia is a serious pregnancy complication characterized by high blood pressure and organ damage. Its causes are not fully understood, and many risk factors -- including first pregnancy, advanced maternal age, obesity, and pre-existing hypertension -- have been identified. Whether dietary patterns contribute to preeclampsia risk remains an open research question, and the specific role of ultra-processed food is far from established.
Inflammatory Markers
Study: A 2023 study in the European Journal of Nutrition found that higher UPF consumption during pregnancy was associated with elevated inflammatory markers, including C-reactive protein (CRP). Chronic inflammation during pregnancy has been associated with adverse outcomes in other research.
This finding is consistent with research in the general population linking UPF consumption to systemic inflammation. However, inflammation during pregnancy is influenced by many factors, and the clinical significance of modest CRP elevations associated with dietary patterns remains uncertain.
Critical context: Every study described above is observational. They demonstrate statistical associations between UPF consumption during pregnancy and certain outcomes, but they cannot prove that UPFs directly cause those outcomes. Pregnant individuals who consume more UPFs may also differ in other ways -- income, education, healthcare access, stress levels, physical activity, and overall diet quality -- that independently affect pregnancy outcomes. These confounders are extremely difficult to fully account for in observational research.
Research Summary: Key Studies at a Glance
The following table summarizes the major studies that have examined UPF consumption during pregnancy. Each study's limitations are included because they are essential for interpreting the findings accurately.
| Study Focus | Year | Journal | Key Finding | Limitation |
|---|---|---|---|---|
| Gestational diabetes | 2022 | Environ. Health Perspect. | Higher UPF intake associated with increased GDM risk | Observational; could not isolate processing from nutrient profile |
| Gestational weight gain | 2022 | JAMA Network Open | Higher UPF intake associated with excessive weight gain | Self-reported dietary data; unable to control for all variables |
| Birth weight | 2023 | Nutrients | Mixed results across multiple studies reviewed | Inconsistent findings; heterogeneous study designs |
| Inflammatory markers | 2023 | Eur. J. Nutr. | Higher UPF associated with elevated CRP during pregnancy | Clinical significance of modest CRP changes uncertain |
| Offspring adiposity | 2023 | BMC Medicine | Maternal UPF intake associated with higher child adiposity at age 3-4 | Postnatal diet not fully controlled; possible reverse causation |
| Preterm birth | 2024 | Am. J. Clin. Nutr. | Suggestive association between high UPF and preterm birth risk | Small effect size; single cohort; requires replication |
Important Nuance
The absence of randomized controlled trials (RCTs) on UPF consumption during pregnancy is a significant gap in the evidence. Ethical constraints make it unlikely that researchers would randomize pregnant participants to a high-UPF diet, which means the evidence will likely remain observational for the foreseeable future. This does not invalidate the findings, but it does mean they should be interpreted with appropriate caution.
Reading these studies in context: Many of the associations reported in these studies are modest in magnitude. A modest statistical association in one or two observational studies is meaningful as a direction for further research, but it is not sufficient grounds for changing clinical guidelines or making strong dietary recommendations. The scientific process is deliberately cautious, especially when the population involved is as vulnerable as pregnant individuals.
Common Ultra-Processed Foods in Prenatal Diets
One of the challenges in discussing UPF during pregnancy is that many foods commonly relied upon by pregnant individuals are, technically, ultra-processed. Some of these serve important functions -- either by providing critical nutrients or by being among the few foods tolerable during periods of nausea.
UPFs That Are Common During Pregnancy
- Saltine crackers -- Among the most common remedies for morning sickness; technically ultra-processed
- Fortified breakfast cereals -- Provide folic acid, iron, and B vitamins; classified as NOVA Group 4
- Prenatal gummy vitamins -- Contain gelatin, sweeteners, colors, and flavors; medically recommended
- Meal replacement shakes -- Sometimes recommended when solid food intake is inadequate due to nausea
- Fortified plant milks -- Provide calcium and vitamin D for those avoiding dairy; contain emulsifiers and stabilizers
- Packaged protein bars -- Convenient source of protein during busy days; typically contain many additives
Why Context Matters
- Not all UPFs are equivalent -- A fortified cereal with added folic acid and iron serves a fundamentally different nutritional purpose than a candy bar, even though both are classified as ultra-processed under NOVA
- Nutrient fortification matters -- Folic acid fortification of grain products has been credited with reducing neural tube defects by 25-50% since mandatory fortification began in 1998
- Tolerance varies by trimester -- First trimester nausea may severely limit food options; prioritizing any caloric intake may be more important than processing level
- Convenience has value -- Pregnancy fatigue is real; foods that require no preparation may be the only practical option on some days
Important Nuance
Blanket advice to “avoid all ultra-processed food during pregnancy” could potentially be harmful. It could lead to inadequate folic acid intake (if fortified cereals are eliminated), unnecessary stress and guilt (which have their own negative effects during pregnancy), or insufficient calorie intake during periods of nausea when only certain processed foods are tolerable. Any dietary adjustments during pregnancy should be made thoughtfully, with medical guidance, and with full awareness of what nutrients might be affected.
The nuance that matters: The question is not whether a food is ultra-processed, but what role it plays in the overall diet. A fortified cereal providing 100% of the daily value of folic acid is serving a critical preventive function, regardless of its NOVA classification. Similarly, crackers that help a person manage nausea and maintain calorie intake are serving an important function during a difficult phase of pregnancy. Context is everything.
Nutrients That Matter During Pregnancy
Understanding key prenatal nutrients -- and where they come from -- adds important context to the UPF conversation. Some nutrients are more readily available through whole foods, while others are more reliably obtained through fortified or supplemented (and therefore processed) products. This is one of the key reasons why the UPF discussion becomes more complex during pregnancy than in general health contexts.
| Nutrient | Why It Matters in Pregnancy | Whole Food Sources | Fortified/UPF Sources |
|---|---|---|---|
| Folate / Folic Acid | Prevents neural tube defects; critical in first trimester | Leafy greens, lentils, asparagus, avocado | Fortified cereals, enriched bread, prenatal vitamins |
| Iron | Supports increased blood volume; prevents anemia | Red meat, spinach, lentils, beans | Fortified cereals, enriched flour, prenatal vitamins |
| Calcium | Fetal bone development; maternal bone maintenance | Dairy, sardines, kale, broccoli | Fortified plant milks, fortified orange juice |
| Omega-3 (DHA) | Fetal brain and eye development | Salmon, sardines, walnuts, chia seeds | DHA-fortified eggs, prenatal supplements |
| Protein | Fetal tissue growth; maternal tissue repair | Eggs, poultry, fish, beans, tofu | Protein bars, meal replacement shakes |
| Fiber | Prevents constipation; supports blood sugar stability | Whole grains, fruits, vegetables, legumes | Fiber-fortified cereals, fiber supplements |
| Vitamin D | Calcium absorption; immune function; fetal bone health | Sunlight, fatty fish, egg yolks | Fortified milk, fortified plant milks, prenatal vitamins |
Important Nuance
Notice that several critical prenatal nutrients -- particularly folic acid, iron, calcium, and vitamin D -- are often more reliably obtained through fortified foods and supplements than through whole food sources alone. The synthetic form of folate (folic acid) is actually more bioavailable than the natural folate found in foods, which is why the CDC recommends supplementation even for people who eat folate-rich diets. This creates important nuance: some ultra-processed products play a genuinely protective role during pregnancy that whole foods alone may not fully replicate.
Bottom line on nutrients: The optimal prenatal diet likely combines whole food sources of nutrients with targeted fortified foods and supplements where needed. This is a decision best made with your healthcare provider based on your individual bloodwork, dietary patterns, and health history. A blanket approach to avoiding all processed food during pregnancy could inadvertently reduce intake of nutrients that have been proven to prevent serious birth defects.
Practical Considerations for Expectant Parents
The research on UPF and pregnancy is informative but early-stage. In the meantime, pregnant individuals face daily food decisions. The following considerations are grounded in both the UPF research and established prenatal nutrition principles. None of these replace the guidance of your healthcare provider.
Pregnancy Cravings and Aversions Are Real
Hormonal changes during pregnancy can dramatically alter food preferences and tolerances. Food aversions -- particularly to meat, vegetables, and strong flavors -- are common in the first trimester. Cravings for specific foods, including processed ones, are a normal part of pregnancy. Working against these signals through rigid dietary rules can increase stress without clear benefit. Eat what you can tolerate, especially during periods of nausea, and focus on nutrient quality when your appetite allows.
Focus on Adding, Not Eliminating
Rather than trying to remove processed foods from your diet, a more constructive approach is adding more whole foods where possible. An extra serving of vegetables, a piece of fruit with lunch, or a handful of nuts as a snack all increase the nutrient density of your overall diet without requiring you to give up foods you rely on. For practical swap ideas, see our food swaps guide.
Fortified Foods and Prenatal Vitamins Are Essential
Prenatal vitamins are not optional -- they are a standard component of prenatal care recommended by every major medical organization. Similarly, fortified cereals and enriched grain products provide meaningful amounts of folic acid and iron. These products should not be eliminated based on their NOVA classification alone. If you prefer to reduce other ultra-processed foods in your diet, do so while continuing to take your prenatal supplements and consuming fortified foods as recommended by your provider.
Budget and Access Constraints Are Real
Fresh, minimally processed foods are often more expensive and less accessible than their ultra-processed counterparts. Pregnancy is not the time to take on financial stress over grocery bills. Frozen fruits and vegetables are nutritionally comparable to fresh and are often more affordable. Canned beans and lentils are minimally processed and inexpensive sources of protein, iron, and fiber. Doing the best you can within your means is sufficient. For budget-friendly strategies, see our budget shopping guide.
Stress About Food Has Its Own Costs
Research on stress during pregnancy has found associations between chronic maternal stress and adverse outcomes including preterm birth and low birth weight. Excessive anxiety about food choices -- sometimes called “orthorexia” or disordered eating patterns -- can itself become a source of stress. The goal of understanding UPF research is to make informed choices, not to create a new source of worry. If you find that dietary information is causing you significant anxiety, discuss this with your healthcare provider or a perinatal mental health professional.
For snack ideas that work well during pregnancy, including options that are easy to keep on hand for sudden hunger or nausea, see our non-UPF snacks guide.
The practical takeaway: If you are interested in reducing ultra-processed food during pregnancy, the most sustainable approach is gradual and flexible. Choose whole food options when they are available, affordable, and tolerable. Continue taking prenatal vitamins and eating fortified foods. Do not stress about days when processed food is all you can manage. And above all, follow the specific guidance of your prenatal healthcare team.
What This Research Does NOT Mean
Given the sensitivity of pregnancy and the tendency for health information to be amplified or distorted, it is important to be explicit about what the current research does not support.
It Does NOT Mean UPFs Cause Pregnancy Complications
The studies described in this guide found statistical associations between UPF consumption and certain pregnancy outcomes. Associations are not causation. People who consume more UPFs may differ from those who consume less in many ways -- income, education, healthcare access, stress levels, physical activity, and overall diet quality -- that independently affect pregnancy outcomes. Until controlled interventional studies can isolate the effect of food processing from these confounders, causal claims are not supported by the evidence.
It Does NOT Mean You Need to Eliminate All Processed Food
As discussed in the nutrients section, some processed and fortified foods play important roles during pregnancy. Folic acid-fortified grain products, prenatal vitamins, and fortified milks all contribute to meeting prenatal nutritional needs. Attempting to eliminate all processed food could lead to nutritional gaps that carry their own risks. A balanced approach is more appropriate than an all-or-nothing one.
It Does NOT Mean Current Prenatal Nutrition Guidelines Are Wrong
The existing prenatal nutrition guidelines -- which focus on adequate intake of specific nutrients, food safety (avoiding raw fish, unpasteurized dairy, etc.), and prenatal supplementation -- are based on decades of robust evidence. The emerging UPF research supplements but does not contradict these guidelines. Your OB/GYN or midwife's nutritional guidance remains the most relevant and well-supported framework for prenatal eating.
It Does NOT Mean You Should Feel Guilty About What You Ate
If you are reading this guide during or after a pregnancy in which you consumed ultra-processed food: the research does not indicate that you caused harm to yourself or your child. The associations found in studies describe population-level trends across thousands of people. They do not predict individual outcomes. Many factors contribute to pregnancy outcomes, and diet is only one of them. Guilt about past food choices serves no useful purpose and is not supported by the evidence.
Many Confounding Factors Exist
Higher UPF consumption during pregnancy is correlated with lower socioeconomic status, lower levels of education, reduced access to healthcare, higher rates of food insecurity, higher stress levels, and less access to fresh foods. Each of these factors independently affects pregnancy outcomes. While researchers attempt to statistically control for these confounders, residual confounding is a recognized limitation of every observational study in this area. The observed associations between UPF and pregnancy outcomes may be partly or entirely explained by these underlying factors.
Final note on this section: The purpose of this guide is to share information, not to create anxiety. Pregnancy involves enough sources of stress without adding food guilt to the list. If you take one thing from this guide, let it be this: the research is early-stage, the associations are modest, and the most important thing you can do is work with your healthcare provider to meet your individual nutritional needs -- using whatever foods work for you.
Frequently Asked Questions
Does ultra-processed food cause pregnancy complications?
No study has proven that ultra-processed food directly causes pregnancy complications. The research that exists is observational, meaning it identifies statistical associations between higher UPF consumption during pregnancy and certain outcomes such as gestational diabetes and excessive weight gain. Observational studies cannot establish causation because many confounding factors -- including income, education, healthcare access, pre-existing conditions, and overall diet quality -- may explain the observed associations. Multiple researchers have explicitly noted this limitation. If you have concerns about your diet during pregnancy, discuss them with your OB/GYN or a registered dietitian who can provide guidance based on your individual health profile.
Should I eliminate all processed food during pregnancy?
No. Attempting to eliminate all processed food during pregnancy is neither practical nor advisable. Some ultra-processed foods serve important nutritional functions during pregnancy. Fortified breakfast cereals provide folic acid, which is critical for preventing neural tube defects. Prenatal gummy vitamins are technically ultra-processed but are recommended by virtually all obstetricians. Fortified plant milks provide calcium and vitamin D for those who are lactose intolerant. Additionally, pregnancy often involves nausea, food aversions, and cravings that limit what a person can tolerate eating. The goal is not perfection -- it is making informed choices where possible while ensuring adequate nutrition. Always follow the specific guidance of your prenatal healthcare provider.
What about prenatal vitamins -- are they ultra-processed?
Yes, most prenatal vitamins -- including gummy vitamins and tablets with added colors, flavors, and coatings -- technically qualify as ultra-processed products under the NOVA classification. However, prenatal vitamins are one of the clearest examples of why the ultra-processed label alone does not determine whether a product is beneficial or harmful. Prenatal vitamins provide critical nutrients including folic acid, iron, DHA, and other vitamins and minerals that are difficult to obtain in adequate amounts from food alone during pregnancy. Every major medical organization recommends prenatal supplementation. The processing level of a prenatal vitamin is irrelevant to its medical necessity. Continue taking your prenatal vitamins as directed by your healthcare provider.
Is morning sickness a reason to eat whatever I can keep down?
Yes. During periods of severe nausea and vomiting, the priority is adequate hydration and calorie intake, not food processing level. Many people experiencing morning sickness find that bland, starchy, processed foods -- such as crackers, dry toast, or ginger ale -- are among the few things they can tolerate. Restricting these foods during active nausea could lead to inadequate nutrition, dehydration, and excessive weight loss, all of which carry their own risks during pregnancy. If you are experiencing severe nausea or vomiting (hyperemesis gravidarum), work with your healthcare provider on a management plan. As nausea subsides, you can gradually reintroduce a wider variety of foods. Do not add dietary stress to an already difficult physical experience.
How reliable is the research on UPF and pregnancy?
The research on ultra-processed food and pregnancy outcomes is still in its early stages. Most studies are observational cohort studies that track dietary intake through food frequency questionnaires and follow pregnancy outcomes. These studies can identify associations but cannot prove that UPF consumption causes specific outcomes. Sample sizes vary considerably, and few studies have been replicated across different populations. Confounding variables -- particularly socioeconomic status, access to healthcare, and overall diet quality -- are difficult to fully control for. Some findings, such as the association with gestational diabetes, have been observed across multiple studies, which adds weight to the evidence. However, no randomized controlled trials have been conducted on UPF consumption specifically during pregnancy, and ethical constraints make such trials unlikely. Treat the findings as informative but preliminary.
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