How exactly does it pay to be fat?

Via Tyler Cowen, I found this article entitled, "It Pays to Be Fat." The thesis:

After controlling for all other attributes that contribute to wages (an individual’s job experience, firm size, region in which they reside, occupation, sector, full or part-time employment, health, education, age, and whether or not they have young children) the author finds that married men and single women both have a wage rate that is positively related to the their Body Mass Index (BMI) – the heavier they are, the higher the wage they are paid. Single men and married women have the opposite experience – they are penalized for their weight -- the heavier they are, the lower the wage they are paid.

Their explanation is somewhat provocative, but a few things seem a little off to me. First, how can you control for "health" when you're comparing people based on level of obesity? Isn't being obese considered "unhealthy"? I'm not sure how exactly this control works. Suppose it means that a thin woman would have to be unhealthy in other ways in order to be considered equal in health to an overweight woman. Perhaps certain causes of lack of health, such as smoking habits, could contribute in some way to lower wages? This may be grasping at straws.

But secondly, what I'm more concerned about is that part of their explanation explicitly states that "heavy women recognize that they may not marry or have the advantage of living in a dual income household. They therefore invest more in their jobs so that they get closer to that standard of living they might have had they married." Um, so, if you don't control for different levels of investment in work, how can you possibly claim to detect some sort of "discrimination"? Either this explanation is false, as it has already been controlled for under "level of experience," or this explanation is true, and there's no discrimination going on.

This stuff becomes news just because it's provocative. I have my doubts about how much sense it really makes. Given how the article ends, I guess it really was just meant as a joke, anyway:

So, there you have it. A new cause for public outcry – slender, single women are under-rewarded in their employment. They should get together with the single, overweight men and demand fair treatment. I doubt it would improve their wages, but it could make for an interesting dating scene.