Ultra-Processed Foods Linked to Reduced Fertility and Early Fetal Development
Ultra-processed foods are increasingly linked to health concerns, including cancer and heart disease. Recent research now suggests a connection between the consumption of these foods and both fertility issues and slower early fetal development.
Even as many fertility experts already advise patients to adopt a healthy diet, guidance has traditionally focused on the dietary choices of women. However, emerging evidence indicates that the dietary habits of both prospective parents—women and men—can impact the chances of conception and the early development of offspring.
The Study Uncovered More Than One Fertility Issue Stemming From Ultra-Processed Foods
Published in the journal Human Reproduction, a study analyzed data from approximately 800 women and 650 male partners enrolled in a population-based study tracking parents from conception through their children’s early years. [1]
Researchers collected dietary data through questionnaires completed during early pregnancy (around 12 weeks). On average, ultra-processed foods comprised 22 percent of the women’s and 25 percent of the men’s total daily food intake. [2]
The questionnaires also provided data on time to conception, the likelihood of conceiving within a month, and subfertility—defined as difficulty conceiving within 12 months or the need for assisted reproductive technology.
Ultrasound data collected at 7, 9, and 11 weeks of gestation allowed researchers to assess fetal development, including the head-to-buttock length (indicating size) and yolk sac volume.
For women, higher consumption of ultra-processed foods wasn’t associated with difficulty conceiving, but it was linked to slightly smaller embryo growth and yolk sac size at seven weeks of pregnancy. This can be associated with a higher risk of negative outcomes, including premature birth, low birth weight, and an increased risk of miscarriage.
For men, increased ultra-processed food intake was associated with a greater likelihood of subfertility. [2]
Researchers noted that while these differences were small, they are significant given the worldwide increase in ultra-processed food consumption. [1]
“Our findings highlight the importance of involving both the mother-to-be and father-to-be in preconception counseling, as health and lifestyle of women and men play an important role in reproductive outcomes,” the study authors state. “It is likely easier to craft sustainable lifestyle changes as a couple.”
The study participants were relatively healthy, limiting the generalizability of the findings to high-risk groups. The observational nature of the study makes it difficult to establish a direct causal link between ultra-processed food consumption and these outcomes.
The Recent Research Supports Earlier Findings
Fertility is a complex process, making it challenging to attribute conception success or failure solely to diet, says Josette C. Dawkins, MD, a reproductive endocrinologist at Boston IVF in Springfield, Massachusetts. However, the latest findings align with previous research linking ultra-processed foods to fertility challenges.
One study published in 2025 found a correlation between a diet high in ultra-processed foods in men and reduced sperm quality and motility. [4]
Another observational study, also published in 2025, linked ultra-processed foods to reduced fertility in women when more than 40 percent of their diet consisted of these foods.
How Diet May Impact Conception for Men and Women
Dietary choices can influence fertility through several mechanisms. “Diet plays an important role in influencing hormone production, egg and sperm quality, and overall reproductive health,” explains Dr. Dawkins.
“For men, zinc, antioxidants, and healthy fats improve sperm quality,” she says. “For women, nutrients like folate, vitamin D, and omega-3s support egg quality and hormone balance, and protect the eggs from oxidative stress.”
A diet high in ultra-processed foods often means a lower intake of whole foods rich in these essential nutrients. These processed foods are often pro-inflammatory and lack key antioxidants like omega-3s, which are important in reducing oxidative stress, potentially impacting sperm DNA and egg quality.
High refined sugar intake, common in many ultra-processed foods, can lead to insulin resistance and hormonal imbalances, according to Sara Mucowski, MD, a reproductive endocrinologist and ob-gyn at Dallas IVF.
Chronic inflammation resulting from continued exposure to ultra-processed foods may also impair sperm and egg development and create a less hospitable uterine environment. The low fiber content of these foods can disrupt gut health and exacerbate inflammation, contributing to fertility issues.
Finally, ultra-processed foods can contribute to overweight and obesity, which can accelerate these negative effects, says Alex Robles, MD, reproductive endocrinologist at Columbia University Fertility Center.
Why Fertility Specialists Emphasize Optimal Nutrition
“Because we are what we eat, it is important that we provide our bodies with the nutrition it needs to function optimally,” says Mucowski. “I recommend that my patients who are trying to conceive focus on whole foods and lean proteins, especially those with omega-3 fatty acids, antioxidants, and high-fiber carbohydrates.”
Both partners should consider their diets. “While this study shows associations rather than causation, it reinforces the importance of a balanced, nutrient-rich diet when trying to conceive,” says Dr. Robles. “Reducing intake of ultra-processed foods and focusing on whole, minimally processed options is a practical step couples can take to support their fertility and early pregnancy health.”
Mucowski suggests aiming for at least 80 percent of food intake from minimally processed foods, rather than complete elimination of ultra-processed options.
“Please pay attention to nutrients, such as folate, vitamin D, antioxidants, and omega-3s,” Dawkins says. “Limit refined sugars, unhealthy fat, and excessive alcohol.”
However, fertility specialists emphasize that dietary changes alone may not overcome underlying medical causes of infertility. “In everything, consult a fertility specialist, as a healthy diet alone will not overcome a medical cause for infertility,” Dawkins says.