I feel compelled to point out that what the fashion industry consider 'attractive' (read: easy to design clothes for) and what the vast majority of straight men consider attractive are not the same thng at all. I don't think I know any blokes who go for very skinny women, and I personally find the more extreme end of the model scale repellent. In just the same way I'm assured by most women I know that they find excessive muscliness in men unattractive.
Interestingly, it's the super-skinny women (i.e. models) that you see in women's magazines, advertising clothes and so on, and the super-beefcake blokes on the front of, e.g., Men's Health (a 'stealth' gay porn mag, if ever I saw one!), while the women found in men's magazines are generally a lot more curvy than catwalk models and I can only assume the men found in women's magazines are a bit more normal-looking that the body-builder look manufacturers of protein supplements would have us believe women go for.
Edit: in specific reply to Woebot, while I think some models are skinny to point of looking unhealthy (and actresses too - what ever happened to Keira Knightly? She looks AWFUL!) I also think the case against them is exaggerated sometimes, especially by use of the American 'size zero', which seems to imply that the woman has ceased to exist at all - it's actually the same as a UK size 6. And you're right, we (in the UK) are an increasingly obese culture; while anorexia is obviously a terrible illness, the fact remains that far more women and men would look and feel better if they lost a bit of weight than if they gained it.