Savage ethics II: What if one partner gets fat?

Sometimes I see Dan Savage as an advance scout, mapping out the ethical terrain of modern romantic/sexual relationships. But beating his way through all of this uncharted territory, he sometimes comes up with ideas that I think require a little further discussion by the rest of us. We had a very productive discussion here at LFaB about Dan Savage and the ethics of cheating, but now Dan has wandered into far more dangerous territory: the ethics of relationships and fat.

I almost hesitate to offer up my blog for such a touchy subject, but I'd kind of like to talk about Dan's conclusions. I'd also like to discuss his little stunt where he showed that his readers were okay with one partner (in a long term relationship) saying to the other "Honey, I'm not attracted to you anymore because of your weight gain -- shape up, or I'm shipping out," if -- and only if -- the partner who gained weight is male.

Dan seems to be of the opinion that it should be okay for one partner to say this to the other and expect results. Perhaps, but there are a couple of very important points that I think he missed:

1. While some people do achieve significant, permanent weight loss, they are the exception rather than the rule. It's not as simple as "anyone can do it if they care enough to do it." This is not from personal experience -- I'm not fat and have never dieted -- but everything I've read indicates that an attitude of "So-and-so did it, so anyone can do it" isn't justified by the evidence.

2. A focus on weight and appearance can be counterproductive when making healthy lifestyle changes. Greta Christina wrote an excellent article about this here. Nearly all of us have lifestyle improvements we could make to be more active and eat healthier. So if two partners decide together on a change they'd like to make (replacing evening T.V. with an evening bike-ride, replacing fast food with actual food), and if the focus sincerely is on health and feeling better about your body, then you have a good chance of succeeding in making a long term, healthy change (even if you can't count on changing your size or shape). And, really, there's a good chance it will improve your sex life. ;^) But too much focus on the scale and the "your not hot enough for me" factor will likely scuttle your efforts as well as your relationship, not to mention possibly produce an unhealthy (yo-yo dieting) result.

All of this doesn't explain the double standard, though, where a weight-loss ultimatum was seen as more acceptable when placed on a man than on a woman. Some will probably contend the Mr. Savage is full of sh-t, and that in fact a man is more likely to leave a female partner for "letting herself go" -- and feel justified in doing it -- than a woman is to leave a man for the same reason. However, considering the volume of anonymous opinions Dan receives every day, I think it's reasonable to suppose that he's right about what his readers believe is ethical behavior. How people in society at large actually behave is an entirely different question from the ethical ideals of Dan's (mostly young and liberal?) audience.

So the questions I'd like to pose are the following:

1. What do you think is an appropriate response when one partner gains a dramatic amount of weight and the other doesn't?

2. Body and relationship expectations for men and women are different. Is there perhaps a justification for having a double-standard on this question? Or not?

What do you think?