ByDaniella Gray
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The food men eat before becoming fathers could leave a lasting mark on their children, according to new research
The findings come from a study published in the journal <a href="https://healthylife7.com/fueled-wellness-nutrition-better-for/” title=”FUELED Wellness + Nutrition | Better-for”>Nutrition Research, which examined 43 father-mother-newborn triads in Ribeirão Preto, Brazil
Researchers investigated whether a father’s consumption of ultra-processed foods was associated with measures of newborn growth and body composition
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Ultra-processed foods include products such as processed meats, sugary drinks, packaged snacks, cookies and other industrially manufactured foods containing ingredients and additives not typically used in home cooking
In the study, these foods accounted for an average of 30 percent of fathers’ calorie intake
After adjusting for factors such as age, education, smoking, alcohol use and physical activity, the researchers found that higher ultra-processed food consumption among fathers was associated with increased birth weight, a higher ponderal index—a measure of body proportionality at birth—and greater skinfold thickness in the thigh and supra-iliac regions of newborns
The findings suggest that preconception health is not solely a mother’s responsibility. Daniela Sartorelli, a professor at the Ribeirão Preto School of Medicine at the University of São Paulo (FMRP-USP) who coordinated the study, said both prospective mothers and fathers should adopt healthy habits before trying to conceive
“Our data suggest that both the mother and the father should follow a healthy diet during the preconception period,” Sartorelli told Newsweek
Sartorelli said the study focused specifically on how diet may affect newborn health, but noted previous research has linked a father’s weight, exercise habits, and use of alcohol and tobacco to child health outcomes as well
“It is therefore suggested that both the expectant mother and father should adopt a healthy lifestyle before conception,” she added
Sartorelli also said the findings support limiting ultra-processed foods before pregnancy
“The data suggest that both expectant mothers and fathers should avoid consuming ultra-processed foods during the preconception period,” she explained. “There is no safe limit for the consumption of these foods, so it is advisable to avoid them in the diet.”
The researchers did not find a significant association between fathers’ diets and overall neonatal body fat, but they said the results suggest paternal dietary habits may influence certain aspects of fetal growth
According to the authors, a father’s influence is thought to occur through epigenetic changes—modifications that affect how genes function without altering the DNA sequence itself
One possible mechanism involves IGF-II, a gene inherited from the father that plays a key role in fetal growth
Previous research has suggested that dietary habits and obesity may alter how this gene is regulated through a process known as DNA methylation
Interestingly, the researchers found that mothers’ and fathers’ diets appeared to have different associations with newborn growth
While greater paternal consumption of ultra-processed foods was linked to higher birth weight, higher maternal intake of these foods early in pregnancy was associated with lower birth weight, shorter birth length and smaller head circumference
The authors said these contrasting findings may reflect different biological pathways through which maternal and paternal health affect fetal development
The researchers cautioned that the study was small and relied on dietary recalls rather than direct observation of eating habits
They also noted that fathers’ diets were assessed during pregnancy and used as a proxy for preconception eating patterns
Because of these limitations, the findings should be interpreted cautiously and cannot prove that ultra-processed foods directly caused the differences observed in newborns
Still, the authors said the results highlight the importance of including fathers in conversations about preconception health and family planning
If confirmed in larger studies, the findings could add to evidence that what men eat before conception may help shape their children’s health from the very beginning
Reference
Carvalho, M.R., Miranda, D.E.G.A., Baroni, N.F., et al. (2026). A higher paternal ultra-processed food consumption is directly associated with parameters of neonatal anthropometry. Nutrition Research, [online] 151, pp.16–25. doi:10.1016/j.nutres.2026.04.015
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