After weight-loss surgery, singles were more likely to start a relationship and couples were more likely to split

Obese patients who had weight-loss surgery were more likely to start a new relationship than their counterparts who didn't have the procedure, a new study finds.
(Symphonie/Getty Images)

Surgical reduction of the stomach may do more than change signals of hunger and appetite, improve metabolic function and induce substantial weight loss. New research suggests it may change some hearts as well.

A large Swedish study has found that obese people who had a spouse or live-in partner and then underwent weight loss surgery were 28% more likely to become separated or divorced compared with those in a comparison group who didn’t have surgery.

Patients who were single before surgery, however, were roughly twice as likely to begin a new relationship afterward as were obese patients who just got weight-loss advice.


Those findings, measured four years after patients underwent bariatric surgery, were magnified in people who lost the most weight. They offer new evidence that while substantial weight loss can buoy an obese person’s self-confidence and rekindle his or her drive to find romance, it can also disturb the foundations of existing partnerships.

It’s a dynamic familiar to David Sarwer, who directs the Center for Obesity Research and Education at Temple University’s College of Public Health.

Many people intuitively believe that a large weight loss will improve a romantic relationship, said Sarwer, who has studied the psychological and social impact of weight-loss surgery for two decades. Of course, they think, “The person who lost the weight will be thrilled and the partner will be pleased with the change in appearance as well,” added Sarwer, who was not involved in the study.

“Unfortunately, weight loss can have negative effects on relationships as well,” he said. “The person who loses weight may feel better about herself and end an unhappy relationship. Sometimes, partners are threatened by the weight loss and that jealously can cause problems as well.”

The authors of the new study acknowledged that while weight loss surgery “may affect the dynamics of the relationship,” assigning blame for breakups would be a more difficult task. Their research did not capture which partner ended the relationship, or why.

Those questions may become more important as bariatric procedures become more commonplace as a means of treating obesity and the metabolic and other disorders that come with it. In 2013, nearly 470,000 bariatric procedures were performed globally. In 2016, 216,000 such procedures were performed in the United States, according to American Society for Metabolic and Bariatric Surgery.


Most weight-loss surgery patients and their partners report that the quality of their committed relationships stays steady or improves, the authors noted. But in addition to reporting feelings of jealousy, some partners of bariatric surgery patients tell researchers they feel “no longer needed” after a mate has undergone such drastic change.

If they’re to have a “better chance of handling potential tensions in their relationship,” prospective weight-loss surgery patients should be informed about this possibility, the authors said.

Divorces and separations were higher among patients who judged the quality of their family relationships to be poorer at the time of surgery. And they were more common among patients who were younger, had been divorced before, or who had been married or living with a partner for shorter period.

But not all ended relationships should be seen as evidence of an “adverse event” of bariatric surgery, the authors cautioned. The increased self-confidence and self-esteem that comes with taking the decision to have surgery, and with the substantial weight loss that results, may have empowered some patients “to leave an unhealthy relationship,” they wrote.

The study, conducted in Sweden, gleaned these insights from a pair of large national databases. One compared patients who got weight-loss surgery with a comparison group of obese people who just got weight loss advice. Another compared changes in the marital status of bariatric surgery patients with that of people in the general population.

After four years, 9.4% of patients who got bariatric surgery reported they had separated or divorced. Among obese patients who got weight-loss advice only, 5.5% had undergone divorce or separation four years later. After taking into account other factors that influence the likelihood of relationship breakups, the authors gauged the increased risk of divorce or separation among those getting bariatric surgery to be 28% at the end of four years.


Compared to a general population (rather than to a comparison population of obese people seeking care for that condition), rates of divorce among those who underwent weight-loss surgery was 76% higher.

The Swedish study also documented one of bariatric surgery’s happier effects: love and marriage.

After four years, 21% of the single men and women who got surgery had entered into marriage or a new romantic relationship. For the obese members of the comparison group who got diet-and-exercise advice only, 11% had done so after four years.

At 10 years out, 35% in the surgery group had married or kindled a new romance, compared to 19% of those in the comparison group.

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