Bath University, in a June 2017 study, concluded that, “Being married makes men gain weight, and the early days of fatherhood add to the problem.”
“There's no effect on male BMI if their wife becomes pregnant, but in the early years after childbirth men gain weight.”
“It confirms the idea that people who are single but seeking marriage have more incentive to stay fit and make more effort than those who are married. It also supports the theory that marriage leads to more social occasions involving richer foods, or more regular meals for men; while putting paid to the idea that married couples have better physical health because of increased social support.”