When it comes to preparing for a healthy pregnancy, the focus is usually on moms. But new research suggests dads play an important role, too.In a study of 43 families, researchers found the more ultra-processed foods fathers consumed before conception, the higher their babies' birth weight and the greater the accumulation of fat in the thighs and around the waist at birth.Higher birth weight and elevated body fat early in life are considered risk factors for cardiometabolic diseases in adulthood.Researchers believe diets high in ultra-processed foods may trigger inflammation in the body, affecting sperm quality and changing how certain genes are expressed before they're passed to a baby.One gene highlighted in the study, IGF-II, (pronouncer: Eye Gee F 2) is inherited exclusively from the father and plays a key role in fetal growth.Researchers say a father's eating habits may change how that gene behaves, potentially influencing fetal development.Moms' diets also mattered, but in a different way. Mothers who ate more ultra-processed foods early in pregnancy tended to have babies with lower birth weights, shorter lengths, and smaller head circumferences.Researchers say the findings reinforce the importance of including fathers, alongside mothers, in health and family planning guidance.Source: Nutrition ResearchAuthor Affiliations: University of São Paulo .Sign up for our weekly HealthDay newsletter