Nutritional research on pregnancy has long concentrated on mothers. A study coordinated at the Universidade de São Paulo's Ribeirão Preto School of Medicine turns attention to fathers, examining 43 triads of fathers, mothers and newborns drawn from the public healthcare system in Ribeirão Preto. Published in the journal Nutrition Research, it links a father's consumption of ultra-processed food to measurable differences in his baby's body at birth.
Higher paternal intake of ultra-processed products, which averaged around 30 per cent of the fathers' total energy and was dominated by processed meats, sugary drinks and biscuits, was associated with higher birth weight and greater fat deposition in the babies' thighs and suprailiac region. Maternal consumption showed the opposite pattern: eating more ultra-processed food up to the sixteenth week of pregnancy was associated with lower birth weight, shorter length and smaller head circumference.
The authors are careful about what the data can support. The sample is small, the findings are associations rather than proof of cause, and no increase in total body fat was detected, only fat accumulation in specific regions. Even so, the study adds to growing evidence that paternal nutrition before conception shapes offspring outcomes, and it strengthens the public health case for targeting dietary advice at both prospective parents rather than mothers alone.