This is pretty weird -- the model who was picture in the supposedly Photoshopped Ralph Lauren ad is 5'10" and 120 lbs, and she says she was fired for being "too fat." Wha???
It just happens that when I started college, I was 5'10" and 120 lbs. No one considered me overweight. I was extremely skinny, and stayed that way the entire year in part because I ran cross-country. No freshman 15 for me, which means someone else gained 30 lbs to balance me out!
Now, I realize that weight for males versus females isn't directly translatable, because men are supposed to have more heavy muscle mass. Still, I gained that mythical 15 pounds over the next four years so that I was 5'10" and 135 lbs when I graduated. I was still considered very skinny. By the time I started law school four years after college, I was 5'10" and 150 lbs. I'm pretty sure that my law school classmates would remember that I was still skinny back then. So even if you can't compare men and women directly, I gained 30 lbs between my weight at the beginning of college to when I went to law school, and I was skinny the whole time. I just can't see how a woman could possibly be considered fat at 5'10" and 120 lbs. I think maybe the term we are looking for is "too skinny"?