Eighty pounds is about 50-70% of an average woman's body weight. To be honest, I would not like it if my husband gained 50-70% of his body weight.  It's not only the way he would look, but I have a hard time believing it would not affect his mood, outlook, energy levels and sex drive. That said, I hope we have enough shared history that I would be patient and supportive to help him solve the problem, but I would never deny there is a problem.

By the same token, I think this is a problem for their marriage, especially if the writer already feels like he wants a divorce. Sucking it up is not an answer. That said, the only way his wife solves this problem is with his wholehearted support. I think he needs to try that. Go to counselling, adopt a healthier lifestyle as a couple and be encouraging rather than judgmental. If she's willing to work at it, they can probably save this marriage. If she refuses, there may be no future for them.