Can't answer "yes" or "no" on this poll because it's honestly not that simple.
Ladies aren't after skinniness, they're after security, and this generally means earning potential. This is because, if their relationship ultimately sees them pregnant, they're going to need someone to see them through that. It makes a whole lot of sense that this would be an instinctively ingrained thing, because ladies who go out and get themselves knocked up by people who leave them to fend for themselves are likely to be an evolutionary dead end.
If you're flabby, the popular prejudice in that regard is that you're lazy. If you're lazy, you're not a very good provider. Thus, the ladies will tend to spurn you in that regard. Cave girl sees flabby layabout, she's not going to be all that interested in him.
However, lets say you're flabby but are in possession of significant earning potential? For example, you're a prominent politician, a rock star, a Nobel prize winner, or are simply raking in the dough somehow? Ladies will beat a path to your door, no lie. Cave girl sees village chieftain - yeah, that's an extremely lucrative platform for evolution, lets horn in on that action.
On the other hand, lets say you don't have significant earning potential, but you're not too flabby, not too emaciated, just have a reasonably capable looking body, and a good positive attitude to go with it? That works, because you've got good earning potential by virtue of having the physical and mental means to bring it about. Cave girl sees capable worker - that'll do.
Having big muscles can be repulsive if you don't seem to do anything particularly useful with them. Many bodybuilders can't move furniture, or so I hear, because they way they built their muscles is mostly for show. It doesn't speak "earning potential" if you spend most of your time pumping up when there's bills to pay. Cave girl sees as much a lout in muscle freak as she does chubby layabout.
Skinniness emerges as a moot point in the larger picture. I'm no lady, but I think I got it figured out well enough.
Now, as to why the Twiggy look caught on in women, that's a trickier question [http://correct-weight-loss.net/2009/07/27/women-starting-to-realize-that-skinny-bodies-are-not-attractive-shapely-bodies-are-beautiful/].