Glad he's been doing well. Parrots, even macaws, are small animals and (compared to human meals) don't really eat a lot. Especially if you're providing a huge dish full of food. It may appear he's barely touched it when in fact he's eaten plenty for his caloric/nutritional needs. Some birds also aren't social eaters so you may rarely see your bird eat if he's one of those types, even though he does when alone. If he's pooping, he's eating. Parrots have fast metabolisms and digestive systems, so they run out of fuel quickly if they don't eat enough.
It is not essential you get one right now, but most bird owners own a special perch scale for weighing their birds regularly (at least once a week, preferably several times). It's a good way to ensure the bird is eating enough. If they maintain weight, even if you don't see them eat much, they still are. Also a good way to monitor for the first signs of illness, which in a parrot is often rapid weight loss.
