Maternal diets high in UPFs may influence children’s health years later

From maternal metabolism to the developing infant microbiome, researchers trace how early exposure to ultra-processed foods may carry health implications across generations.

Proposed mechanism linking maternal UPF intake to gut–brain axis disruption. Image adapted from López-Yerena, A., Pinto, V., Stella, B. M., Yaşar, E., Camafort, M., Vives-Giralt, M. Q., Casanovas-Garriga, F., Ruiz-Leon, A. M., Estruch, R., & Casas, R. (2025). Unhealthy Diets, Unhealthy Futures: How Modern Eating Patterns Endanger Maternal and Offspring Health. Nutrients, 18(14), 2320. https://www.mdpi.com/2072-6643/18/14/2320 using ChatGPT/OpenAI

In a recent review published in the journal Nutrients, a group of authors summarized current evidence on how consumption of ultra-processed foods (UPFs) during pregnancy and early childhood is associated with adverse maternal health outcomes, offspring development, and gut microbiota, while exploring the biological, psychological, and social factors involved.

Background

Can the foods consumed during pregnancy shape a child’s health long after birth? The consumption of UPFs has attracted global attention because these products are often high in added sugars, saturated fats, salt, and food additives, while being low in fiber and essential micronutrients.

Epidemiological studies consistently associate higher UPF intake with obesity, type 2 diabetes, and cardiovascular disease.

Pregnancy and early childhood are particularly sensitive life stages during which nutrition can influence metabolism, immune function, and the gut microbiota, with potential implications for health throughout life. 

Literature Search and Evidence Overview

The authors conducted a narrative review by searching the databases PubMed, Scopus, and Google Scholar for relevant English-language publications reporting human evidence, with no publication date restrictions, through January 2026.

Animal experiments and laboratory studies were excluded from the review. In total, 84 publications were reviewed, including 71 original research articles, five systematic reviews and meta-analyses, and eight narrative reviews. 

The findings were classified into three interrelated themes: current consumption trends, health implications, and a proposed biopsychosocial pathway linking UPF exposure to maternal and child health.

Global Trends and Maternal Health

UPFs are becoming increasingly common worldwide due to their convenience and widespread availability. Packaged snacks, sugary beverages, ready-made meals, sweetened cereals, and processed baked goods are now a major part of daily intake in many countries. Their growing consumption reflects globalization and changes in food systems. However, the review notes that there are no universal thresholds defining high UPF consumption, as most studies use population-specific categories such as tertiles or quartiles.

Several studies have associated higher UPF consumption during pregnancy with poorer diet quality, as expectant mothers report lower intakes of protein, fiber, vitamins, and essential minerals along with higher intakes of sodium and trans fat. Evidence summarized in the review also links higher intake with excessive gestational weight gain, maternal obesity, gestational diabetes mellitus, preeclampsia, increased inflammatory markers, and postpartum weight retention.

Some research has further linked periconceptional UPF consumption with impaired embryonic growth, while intake before pregnancy has been associated with a higher probability of gestational diabetes, particularly among women aged 30 years or older.

Higher consumption is also associated with increased levels of stress, anxiety, sadness, and depressive symptoms during pregnancy. However, the review notes some inconsistencies across studies. Although most of the findings come from observational studies, their consistency supports public health strategies to reduce UPF exposure during pregnancy.

Biopsychosocial pathway model illustrating the impact of UPFs on maternal and infant health. 

Gut Microbiota and Early Childhood Nutrition

Pregnancy naturally alters maternal gut microbiota in ways thought to support maternal metabolism and fetal development, but diets rich in UPFs may further disrupt these microbial communities.

The review suggests that components common in UPFs, including emulsifiers, refined sugars, artificial sweeteners, and saturated fats, may alter microbial metabolism, increase intestinal permeability, reduce short-chain fatty acid production, and promote low-grade inflammation. These proposed pathways could contribute to impaired immune regulation and metabolic health and could alter the transmission of beneficial microorganisms from mothers to children.

The review also highlights that consumption of UPFs begins early in life. Products classified as ultra-processed under the NOVA system can include some commercial infant formulas, baby snacks, breakfast cereals, ready-made meals, and sweetened dairy products. However, the World Health Organization (WHO) recommends exclusive breastfeeding during the first six months of life and continued breastfeeding alongside complementary foods until two years of age or beyond.

Maternal dietary habits strongly influence children’s eating behaviors, while shorter breastfeeding duration, lower maternal education, socioeconomic factors, food marketing, and prolonged screen time are associated with greater intake of UPFs.

Infancy is a critical period for the development of the gut microbiota. The evidence summarized in the review links early UPF exposure to altered microbial composition. One Brazilian cohort found higher levels of Bifidobacterium among breastfed children who did not consume UPFs than among weaned children who did. However, feeding status complicates attribution, and the wider findings concerning this genus remain inconclusive.

Separately, childhood UPF consumption has been associated with obesity, less favorable lipid profiles, chronic inflammation, food allergies, and anemia. One study also linked higher maternal UPF consumption during the third trimester with poorer verbal functioning in children at ages 4 to 5 years. The review does not establish that changes in the microbiota caused these outcomes.

Infant Feeding and the Biopsychosocial Pathway

Infant formula remains a safe and nutritionally appropriate alternative when breastfeeding is not possible, sufficient, or medically appropriate, although it does not fully replicate the biological properties of human milk. Breastfed babies tend to have gut microbiota enriched in genera such as Bifidobacterium and Lactobacillus.

Trials indicate that different formulas supplemented with prebiotics, probiotics, postbiotics, or bovine milk-derived oligosaccharides may promote microbial profiles more similar to those of breastfed infants, although they do not fully reproduce them.

The review also notes that dietary diversity and some complementary foods may support microbial development, whereas cereals made from refined and hydrolyzed flours were associated with a less favorable profile than cereals containing 50% whole grains and less sugar.

To explain these complex relationships, the authors propose a conceptual biopsychosocial pathway model. Biologically, UPFs may alter maternal and infant gut microbiota, increase inflammation, and influence metabolic and immune development. Psychologically, stress, anxiety, and depressive symptoms may encourage emotional UPF consumption.

Socially, aggressive food marketing, socioeconomic inequalities, and work-related barriers that limit breastfeeding and access to healthy, home-prepared foods may perpetuate less healthy feeding patterns. 

This model is a conceptual framework rather than a demonstrated causal pathway.

Conclusion

The review concluded that high consumption of UPFs during pregnancy and early childhood is an important public health concern with potential intergenerational consequences.

The synthesized evidence links higher UPF intake with poorer maternal diet quality, metabolic and obstetric complications, microbiota alterations, childhood obesity risk, and potential immune-metabolic and neurodevelopmental effects.

Although the available evidence is primarily observational and cannot establish causality, the consistency of reported associations and their biological plausibility support reducing exposure during these critical life stages. 

The authors emphasize that public health strategies that reduce UPF exposure while supporting nutritionally adequate diets, along with further high-quality research, are essential for improving maternal and offspring health outcomes. Further research is needed to clarify these relationships and develop effective nutritional interventions.