Once again, thanks for your input. I think if this little fella went through the typical "phases" of eating that you mentioned above, I wouldn't question it. My own kids eat like birdies some days and horses others!!
But you are right, striking a balance is key. I was looking at him the other day, and (as I mentioned) he is a sturdy boy. Understandably, he eats more than some kids. But I will continue to use my own judgement, at least a little, when serving him.