If there’s one aspect of the child-rearing process that deserves more attention and consideration, it’s the effects on the male body.

No no, but there is a study out today that looked at 10,253 men and found that young, first-time dads gained an average of 4.4 pounds, while their childless peers actually lost 1.4 pounds. Researchers at Northwestern University’s Feinberg School of Medicine are calling this the “fatherhood effect,” a mildly academic take on “dad bod,” the term for mid-life male physique as a product of paternal indolence that enjoyed two seconds in the sun in April before being commercialized and basing out (v. becoming basic, reaching a linguistic-cool nadir).

Even if the weight gain doesn’t seem immediately surprising, it may offer a glimpse into the typically impenetrable male mind and the nature of health motivation. “I've been studying fathers for a while now,” lead researcher Craig Garfield told me, “and I've always been interested in how becoming a father leads men to think about what they're doing with their lives.”

What Garfield has found is a renewed sense of interest in health, if not to be good role models then because men want to live to see their children grow and prosper. In his research and clinical work as a pediatrician, men tend to tell him that becoming a dad was a “magical moment” for them, when they became inspired to eat well, stop smoking, drink less, et cetera. Living for reasons bigger than oneself, imbued with love and connection, is the advice of many health gurus. In that way, the weight-gain findings are a little unexpected.

But reason and action are not the fondest of bedfellows. Garfield and colleagues speculate that despite noble intentions, new fathers eventually end up with less time and energy to exercise and sleep and relax, and with more leftovers and plates to clean. Health is only as robust as a person’s environments; our bodies are products of circumstance.

One day, building on today’s findings could inform preventive recommendations that could affect all parents. In the meantime the lesson is, guys, if you want to get that tight beach body ready for swimsuit season, don’t bring a child into the world.