How Fatherhood Changes the Body & Brain

For most kids, there's no hero, no protector, no man more seemingly invincible than dad. Seeing a new dad hold his baby for the first time can be downright swoon-worthy. But there is a reason we use the expression, "fatherhood changes a man."

Becoming a dad first alters a man's brain. Both the University of Denver and the University of Michigan have studied fathers' brains through MRIs. While men's brains don't respond to a baby's cries as quickly as mothers' brains in the first few weeks, there is a shift between 12 and 16 weeks.

In moms, core brain areas responsible for nurturing and risk assessment were most active during MRIs, while dads' images light up more in regions of the brain that control thought, goals, planning and problem-solving. However, stay-at-home dads' brains are much like a mom's by the 4-month mark.

That bond pays off. The National Fatherhood Initiative reports that the more time dads spend with their children, especially in the first 10 years of a kid's life, the less likely children are to have behavioral problems in school. It also correlates to better performance on reading tests, so keep reading those bedtime stories, dads!

Changes aren't limited to a father's brain. There's a reason the term "dad bod" exists—but it shouldn't be used as a negative phrase. Fathers might notice they've packed on a few pounds since their babies were born. Both moms and dads find less time to work out after they have kids. A Kansas State University study found that both parents felt guilty leaving their children—even if it was to get in a short workout. While women felt social pressure and guilt if they put their needs before their family's needs, the same hadn't been studied among dads. The researcher found it was common for fathers to split their lunchtimes between eating and exercise to focus more on their families when they got home from work.

Dads also battle chemical changes in their bodies. Several studies have found that testosterone decreases significantly once a man becomes a father—sometimes dipping as soon as the day after his child is born. Researchers believe this is a natural pivot from seeking a mate to maintaining a relationship with their partners and rearing children. Lower testosterone levels also make it more likely for a man's body to release "feel good" hormones like oxytocin and dopamine.

And while it's common to hear about hormonal and psychological changes occurring among mothers shortly after a baby is born, moms aren't the only ones who experience postpartum depression. According to the American Academy of Pediatrics, it's pretty common among dads, too, affecting up to 25% of fathers. And, that number can jump to 50% when his partner has postpartum depression as well. New fathers suffering deparession may become more irritable, lose interest in activities, work all the time, distance themselves from family or feel hopeless and overwhelmed.

Most fathers love the joy of parenting and reap the health benefits, including a sense of purpose, playtime, and the best possible motivation to stay healthy – your kids. So to all the dads out there, we wish you a very Happy Father's Day!

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