Here's another interesting article:
http://www.musclearticles.com/archives/272 ( here's a review of the study..
http://evidencebasedfitness.blogspot.com/2007....n.html)
Generaly speaking, it is well accepted that the type of protein has an impact on body composition: whey is better at building muscle than casein for instance, while casein is more anti catabolic.
Also, a diet high in protein seems to stimulate fat loss more.
I know that nutrient timing is important in Poliquin's view. The guy trains in my gym sometimes and I know the post workout shakes that he takes.. It contains 3 scoops of whey, 10g of glutamine, and 800 cal of carbs. I calculated in all it's over 1200 calories. And he probably doesn't take BCAAs because they don't have it at the gym to put in the shakes. And that's for a guy who is not so big, he weights probably 180-190lbs, not more.
The guys who do DoggCrap also eat a hell of a lot after their training, over 1000 cal in general.
It's surely not just a matter of calories.. nutrient timing and other factors may play a big role.
This being said, I guess that the calories contained in 1 lb of muscle have to come from somewhere. 1 lb of muscle contains about 400-500 calories ( 454g x 28% of protein + a little bit of glycogen). The process of building 1lb of muscle probably also requires energy.. So it may still require a minimum amount of energy. Which doesn't mean that muscle cannot be built in caloric deficit.. the body may build muscle from the proteins in the diet and get the rest of its energy from the rest of the diet and bodyfat.