Well this is what I know based on scientific study and evidence. A calorie is a calorie. Yes. BUT here's what I think is best if you take into consideration how the body demands and uses macronutrients and there indirect effect.
A.Keep your protein at a moderate level. High protein can raise GH but can lead to low testosterone, get the best of both worlds....look it up. This will give you enough to heal from workouts and the like but not give you so much that your body has to use gluconeogenesis to convert the excess, which, protein being expensive most the time, a waste.
B.Keep your carbs at about double your protein, so if you're taking in 100 grams of protein, make it about 200 grams of carbs. This allows the stimulus of insulin which puts the neccessary building blocks of protein into the muscle cells. BUT, keep the majority of them low GI as a rapid rise in blood sugar will lower growth hormone levels...look it up. As we know as well, if insulin is high, glucagon will be low. The amount of fat burning will be significantly reduced, so keep that insulin secretion at a steady rate for that reason. Keeping the carbs at this level helps maintain test levels aswell...look it up.
C.Eat mainly saturated and monounsaturated fats as these are the only fats that raise testosterone, particularly animal fats, which you will get from lean cuts aswell. Polys are good for the heart but don't raise test. Obviously get in your EFA's to cover brain health, heart health and the other plethora of benefits.
On the subject of GH. Remember, GH is useless without the benefit of insulin! So YES low carb diets raise GH, but you need the aminos at hand in the cell to reap the benefits! Also, keep the carbs low glycemic at night especially as you can almost entirely stop the GH released during the first so many hours of sleep and keep the carbs low glycemic after a workout also! In fact, I make a point of waiting at least 45 mins before I eat and it's usually lower in carbs to gain the benefit of GH release.
20 percent protein 40 percent fats 40 percent carbs. All in all a 3000 calorie diet would be something like 150 grams of protein, 300 grams of carbs and roughly 135 grams of fats. This would be an optimum diet in my opinion based on scientific evidence.