Fat sitcom husbands
Slate

... several shows pair extremely attractive women, who are often clad in plunging tops and tight jeans suitable for a Maxim photo spread, with TV husbands who are not only not studly, but downright fat.

I don't know why it took me a year-and-a-half to find this article (maybe because I read Slate that often) but I've been wondering about this for a few years and King of Queens and Grouded for Life were the most prominent mismatches I had noticed.