Agreed with Base, sort of. Calorie for calorie, you can attain the same size/strength whether the nutrients come from a McD's burger or boiled chicken breast. The difference is all of the other crap - the highly processed, preserved, additive-infested junk that you're putting in your body. Between the body fat and the other negatives Base listed, I think the choice is obvious in the case of a BBer.

The only part I disagree with is saying you don't have to be healthy to get lean; I don't think this is true for most people. Somebody who eats a calorie restricted diet of McDonalds might not get FAT - but I don't believe their body will look 'lean'. I think they would have the skinny fat look for sure.