A book that covers all the species of companion and aviary parrots we keep would be the size of the Encyclopedia Britannica - you are, most likely, too young to remember it but it was the HUGEST set of books! And, in all honesty, I really do not know enough about all the species - not that this has stopped other people from writing generic books about parrots as if a parrot was a parrot was a parrot and all could be fed and treated the same way - which is most definitely NOT true. One can draw parallels and similarities between species of the same genus (like amazons, macaws, cockatoos, poicephalus, etc) but each species has different needs and characteristics. But, in all honesty, all one has to do is go to nature. Study the species in the wild, look at the size of the flocks, where they live (geographically) and what kind of climate they evolved to live under (look at the weather patterns and compare them to when their breeding and resting seasons are), study their reproductive behaviors (like, when they become sexually mature and when they take a mate -which is usually NOT the same age, how long are the babies in the nest, how long do the parents feed them in the beak, when do they move away from their parents, do they leave their flock to find a mate? etc), what they eat (and don't go by just the stupid list that read something like: seeds, nuts and fruits - look at the flora of the country and check each plant in terms of whether they eat the fruit, buds or nuts, read biologists and ornithologists field reports where there are observations of flocks feeding in the wild, etc). It's time consuming and a lot of work but the info IS there and, when you find it, try to copy as close as possible what their life in the wild would be. It's as hard and as simple as that.
Now, macaws are late risers - not so much in terms of waking up because they all wake up with dawn but they always wait about an hour before they start eating their breakfast (other species start eating as soon as there is the smallest amount of light in the horizon - like caiques and budgies, for example, that start eating when one would think it's too dark to see the food). This works out great for their keepers because it gives them time to clean the cage and put the breakfast out in peace. They are canopy feeders (meaning they are not ground foragers so they like to get their food high up, never close to the ground so put his food dish all the way up in his cage) and consume HUGE amounts of fruit and fresh plant material so, while they do need the protein (they eat things like palm nuts in the wild), they also need A LOT of produce and prefer large pieces or items they can hold in their 'hands' (so chop is never a good idea for macaws). They leave the nest when they are between 3 and 4 months old but the parents still supplement their food intake up to nine months of age (yours should be near the age when they no longer get supplemented).
For a macaw, I would make a gloop of large grains (mind you, I had two macaws in my rescue and they ate the same gloop I gave to everybirdy else so it's not as if they cannot eat the 'regular' gloop) - like kamut, spelt, oat groats, hulled barley (don't get the 'regular' pearled barley because it's too little), wheat (hard red winter or soft white spring) or, if you find a nice size one, farro. You can also add some big whole grain couscous to the mix but cook it separately because if you do it mixed with the grains, it will become mush. The grains need to be cooked al dente (meaning swollen with water, soft on the outside but still hard in the inside - boil them for 20 - 25 minutes and, when they are done, if there is still water in the pot, put the grains through a colander because at least my birds do not like soupy gloop) and I would advise you to add some beans to the mix (I only add lentils now but I used to add small white beans - do NOT use colored beans, only white ones and, for a macaw, you can use the Northern or Navy ones that are larger in size) and, if you buy them dry and cook them yourself, make sure they are cooked at a high temperature and thoroughly (no simmering for beans, rapid boiling is safer because of the bad lectin that needs to be nullified with cooking). Start him on just grain/bean gloop and add some seeds or nuts to it (just a little bit, mind you) so he can tell the grains are also food. At the beginning, he will just eat the seeds and leave the grains but, eventually (it usually takes 2 or 3 days), he will start eating the grains, too. When you see little white, almost transparent, empty 'skins' in the dish, you know he is eating the grains (they 'peel' the covering and eat the insides). Once he has been eating the grains without a problem for a few days (with parrots EVERYTHING takes a loooong time because it has to be very gradually), start adding sweet corn (they all love corn), when he is eating the corn for a few days, add sweet peas, when he is eating the corn and the peas, add diced carrots, and so on and so forth until he is getting the whole recipe. Also, you will need to add flavorings to each day (they will eat it 'plain' but the changing flavors keep them interested in it) - things like chili powder or any kind of hot spicy peppers (habaneros, jalapenos, chile de arbol, white and black pepper, oregano, cinnamon (but make sure it's the Ceylon one and not the fake cinnamon that is cheaper), ginger, allspice, paprika, etc. Make sure you do research on them so you do not overdo it because you need to be careful with some spices - like nutmeg, for example, that, when taken in a higher dosage causes diarrhea. And you can also add things like chopped raw peppers, chopped sundried tomatoes, organic, naturally dried apple chips (never give a parrot any fruit that has been treated with sulfites -like dried aprictos- or has added sugar -like dry papaya), black olives (only the no salt kind), etc. Check this site for organic and naturally dried produce you can add:
http://barryfarm.com/ To give you an idea, I make a gloop flavor I call 'Apple Pie' that has organic, naturally dried apple chips (from Barry Farm), a bit of cinnamon, some organic raisins and a little bit of grated (remember to wash it first with soap and warm water) organic lemon peel. The Pizza flavor has peppers, black olives and sundried tomatoes with some white pepper and the tiniest sprinkle of garlic. The Pina Colada has dried pineapple chips and unsweetened coconut flakes. While the Chili is just the regular gloop with some chopped sundried tomatoes and chili powder. You see where I am going, right? Just think of a human meal or drink and make it bird-worthy.
Let me know if this is enough.