Divorced men hit the gyms as soon as they sign their legal papers, but lose their tone following another trip down the aisle, according to a new study from the Harvard School of Public Health.

While men shape up following a separation or divorce, they gain back the lost weight when they remarry, likely due to lifestyle changes.

The study, confirming the existence of the so-called “remarriage bulge,” was published in the Journal of Epidemiology Public Health.

The study’s conclusions are based on a sample of 50,000 males in the medical profession, who have been tracked since 1986.

P. Mona Eng, the primary author of the study, began her research with an interest in chronic disease and went on to collaborate with experts in the field of behavioral health, according to Associate Professor of Epidemiology and Nutrition Eric B. Rimm, who advised Eng’s research.

Originally, Eng was not interested in the effect of remarriage, but as individuals in the study remarried, evidence for a “remarriage bulge” emerged.

“Separated and divorced men begin exercising more and eating differently,” Rimm said. “They have different priorities and [a] different use of time.”

Even though divorced men tend to consume fewer vegetables and eat out more, the increase in exercise likely explains the weight loss trend, the study says.

The study finds that divorced men aged 40 to 75 are more physically fit than their married counterparts, but upon remarriage—with a more regulated lifestyle, more time spent eating and more home-cooked meals—men regain the lost weight.

Rimm said that given how little attention has been paid to the topic, he was unsure how the study would turn out.The study concludes that doctors should pay closer attention to divorcees’ physical health. Rimm said that he hopes the findings will lead to improvements in the divorcees’ clinical care.

“Now that we are aware of the physical impact of marital status changes, physicians should acknowledge this fact when caring for patients,” he said.

Much of the current research tracking post-divorce trends focuses on the economics of divorce and parenting strategies for divorced couples.

The study also found that, while divorcees are slimmer, they are more likely to smoke and likely to consume more alcohol than married men with similar backgrounds.

Rimm said the study creates the potential for a “public health intervention,” in which treatments and responses to divorce are informed by the study’s findings.

He added that he hopes future studies will focus on the impact of divorce and remarriage on women.