I'm not sure it's even going to slow down muscle growth. Most of the stuff I see looks at eating protein just before, during, or after the workout, and the short-term differences in protein synthesis, assuming that a greater peak in synthesis=more muscle built. Which isn't necessarily true, synthesis could rise higher without net synthesis over the 24 hour period or more being any greater. Nutrition around workouts is very important to the bottom lines of the supplement companies and websites/magazines that are sponsored by them, I'm fairly skeptical about the whole thing.