A guy welcoming his first child into the world often expresses a deep desire to become a better man and vows to shape up so he can “be there” for years to come.

Then comes parenthood — and with it, an average weight gain of 3 to 5 pounds for a man who lives in the same home as his child. Over the roughly six years following the birth of their first child, live-in dads picked up an average of about 0.6 BMI units. For a 5-foot-10-inch man weighing 175 pounds, that is a gain of about 4 pounds.

During the same period, the average BMI of men who have not fathered a child tended to decline slightly.

Why do dads’ weights matter? Research finds that an overweight or obese father has an outsized influence on his children’s weight. In families where the father is overweight and the mother’s weight is in the normal range, one study found that children tracked over four years were more than four times likelier to be obese than in a family where both parents had normal weights. If the father is obese, the odds of his children becoming so were nearly 15 times higher.

Los Angeles Times