"Here's an idea... Be a man. Did Charleton Heston ever give a shit about his abs? Charles Bronson? Clint Eastwood? The fucking DUKE?"
And while I agree with the sentiment, a) Heston, Bronson, and Eastwood were all in really good shape, and b) if these guys were trying to work in Hollywood as young, unestablished male actors now, you bet your ass they'd be worried about their abs. I'm not saying that's a good thing. In fact it's probably not a good thing. But in the end, staying skinny is, for a certain portion of the acting community, a job requirement.
Unless you're Jonah Hill, I guess. Then it's optional.