You do NOT have to eat every 2-3 hours to grow.
Supplement industry will advocate otherwise, since producers of proteins and amino acids are well aware of the fact that most people simply cannot afford to eat every 2-3 hours and hence will tend to drink a shake.
Do NOT fall for the ''catabolism argument'' when you see or hear it. Your body will NOT get into ketosis especially if your 3-4 meals consist of slow digesting protein and carbs.
I eat a 12oz lean steak as the last meal of the day. This is usually 2 hrs before I go to sleep. It takes about 10-12 hrs for your body to fully digest and metabolize red meat -meaning constant flow of amino acids in blood stream in this time frame- and only sleep for about 7 hrs. Do the math now. If anyone comes around and tells me that my body has gone catabolic because I did not wake up and drink a shake a few hrs after I went to sleep, I would bitch slap that person for parroting the supplement industry.
As for the delay between meals having an effect upon fat loss, eating every 2-3 hrs obviously has an inhibiting effect as opposed to fasting in between meals.
Now, one may ask why most pro BBs eat every 2-3 hrs. Well, if I were to stay on high doses of every anabolic invented so far throughout the year with a specific goal in mind that is turning into a monster, I too would make sure I eat as many meals as possible throughout the day.