New Dad, New Bod

First-time fathers gained weight after first child

It turns out that "dad bod" may be a real thing.

A new study from Northwestern University found that men tended to gain weight after the birth of their first child — even when they didn't live with their children.

"Fatherhood can affect the health of young men, above the already known effect of marriage," said lead study author Craig F. Garfield, MD, a professor of pediatrics and medical social sciences at Northwestern, in a press release. "The more weight the fathers gain and the higher their BMI, the greater risk they have for developing heart disease as well as diabetes and cancer."

Body mass index (BMI) is a measure of body fat based on height and weight.

Dr. Garfield and team followed more than 10,000 men from adolescence into young adulthood, controlling for other factors that could contribute to weight gain, such as age, race, education, income, daily activity and marriage status.

New dads who lived with their babies had an average BMI increase of 2.6 percent between the time of their first baby’s birth and the end of this study.

Nonresident dads had an average BMI increase of 2 percent.

The actual time period for this weight gain varied depending on the age at which the man became a first-time father.

Nonresident fathers became first-time dads at an average age of 22, while resident fathers became first-time dads at an average age of 26.

No weight gain was found in the men who did not become fathers. In fact, these men lost a little more than 1 pound on average after age 23.

"You have new responsibilities when you have your kids and may not have time to take care of yourself the way you once did in terms of exercise," Dr. Garfield said.

According to Dr. Garfield, a pediatrician may be a good person for new dads to talk to about this issue.

"New dads are coming into the health care system as a pediatric chaperon," Dr. Garfield said. "This is an opportunity to talk about things that are important for dad's health and the child's health and to offer dads nutritional counseling and mental health education."

This study was published in the July issue of the American Journal of Men’s Health.

The Eunice Kennedy Shriver National Institute of Child Health and Human Development funded this research.

No conflicts of interest were disclosed.