Eggs & Whey: Building Muscle and Losing Fat with Protein Sources Which Are High in Leucine

Eisenmann et al. report on the effects net effect of feeding rats with different protein sources on changes in body composition and muscle mass:

Leu content of the meals increased muscle weights and was inversely correlated with bodyfat and these outcomes were associated with greater phosphorylation [=sign of "muscle anabolism"] of 4E-BP1 and S6K and MPS in animals fed egg and whey.

With egg and whey protein having the highest amount of leucine among the standard protein (wheat, soy, egg, or whey with 6.8, 8.0, 8.8, and 10.9% leucine) sources of a typical fitness oriented diet, my take on the leucine craze is that the need or possible benefit of additional dietary leucine still has to be established. If you are interest in the arguments pro/against supplementation of leucine in isolation, I suggest you visit my "Leucine Thread" on the Mind&Muscle Bulletin Board.