He is so young, I would definitely keep constant food in the cage for now, non-perishable if it will be in there all day. He's still going to grow a little bit and needs the extra energy. Lots of fruits and veg in as wide a variety as possible NOW when he's young and learning what to eat. Much easier than trying to switch later in life. My AV advises against feeding too much in the way of leafy greens, as these are not part of an amazons natural diet (this was surprising to me, but also makes sense, they aren't ground foragers). I personally offer my bird fruit in the morning feeding and low sugar veggies in his night feeding.
Amazons are actually notorious overeaters and prone to obesity/developing unhealthy eating habits. I find feeding my BFA 2 meals a day with just foraging treats (no dish of food) during the day suits him well. He maintains a healthy weight and eats most of what he's offered in his 2 feedings/enjoys foraging. This is also beneficial for future training endeavors , as you can do a session right before the evening meal when he's very food motivated without having to do a training diet like many professional trainers suggest. I would consider switching your baby to 2 set feedings and discontinue free feeding once he's a year or 2 old. Start teaching him foraging behaviors now and you can leave 'snacks' in his cage to forage during the day. I also strongly recommend you invest in a gram scale and discuss with his vet what they think a good 'adult' weight for him would be, as he will undoubtedly put on a few grams as he grows up. Weigh him regularly, as it's one of the best gauges of parrot health since they tend to hide illness. They will fluctuate a little +/- 5 grams, but a sudden significant loss or gaining of weight as older juveniles/adults can indicate illness. It is likely for the next year or so, your baby will gain some weight just because he's still growing
but it's a good habit to get into weighing him regularly for the rest of his life.
