MI, you are not being touchy. I'm in a towering rage about unconnected matters and you are all being very accommodating of me ranting rather too much on this thread.
LLF, I have no links for this, but I read a while ago that most women find men who are toned but not particularly muscular the most attractive. I think this may also be true of what men prefer women to look like. Rather more extreme images of muscular men and busty but skinny women are then shown in magazines, but men and women tend to claim that isn't what they actually look for in a partner.
The issue then seems to be that women (as a group, not all of them) are prioritising getting that preferred figure over other things they would rather do, be it eating 20 cream cakes sitting on a sofa or going out to be the best rower they can be. Men (as a group, not all of them) seem much less concerned about appealing to the largest number of women, and seem keener on looking a way that increases their supposed power to other men. That means looking big; be that by building up muscle, or just becoming fat, and by emphasising that largeness, be it due to fat or muscle by wearing clothes that emphasise their largeness. This seems to come to its extreme conclusion in aggression in pubs at weekends - chubby shaven headed football hooligans posturing and glassing each other, because lets face it they'd be weaklings in an actual fair fight in a Greek gymnasium!
So rather than wondering why women make an effort to look attractive for men, I wonder why men make so little effort to look attractive to women. I think if women had more economic power and freedom, men would be concerned with appealing to women through physical appearance rather than each other.