As far as using amino acids to promote protein synthesis, I believe 4-5 hours between feedings was the figure in the research. This was using a whey/casein blend. The whey provides the initial spike to jack up protein synthesis, and the casein keeps the levels high enough to inhibit protein breakdown thereafter.
Obviously CH pulses provide an even higher peak, but I believe the four hour figure is still good. You could get in 4 meals plus a protein shake before bed and be in good shape.
Of course, there are those who are convinced that meal timing and frequency are irrelevant and overall calories and macronutrient ratios are all that matter. In that case, the best thing you can do is pick the meal frequency to which you're best able to adhere.
Frankly, you may need 6 meals the day after the fast to get in the extra calories, assuming you're in a mass phase. I usually have 4 meals plus my workout shake, and I'm planning on bumping that up to 6.