I hope it's OK that I jump in here, even though I have not yet had WLS or plastic surgery. I was never really overweight until I married, although I'd always struggled a little to maintain reasonable weight. I apparently married someone just like the father who'd ignored me all my life, and when he continued that pattern in our marriage, I began eating to stuff down anger. Our marriage lasted about 22 years - we are still married but have been separate for a year now, at my request. It took me over a year of therapy (which I entered to deal with emotional eating) to get the courage to end my marriage and ask him to leave. I had planned to file for divorce this month (since my state required a year apart before filing) but now I've decided to have WLS, so I'm holding off on filing until I get it done, b/c I'll have to change insurance once the divorce is final.
So, I think in many cases (obviously not all) people who overeat in the first place may have problems in their marriage but use food to cover their emotions. Once you start dealing with those emotions fully, without food, it may lead to divorce if the other person is not willing to work on it (mine had no interest in looking at himself or our relationship).