My 5 month old will only eat 2-3 oz/feeding; so he is eating once or twice every 1.5 - 2.5 hours. I'd like for him to…

My 5 month old will only eat 2-3 oz/feeding; so he is eating once or twice every 1.5 - 2.5 hours. I'd like for him to start consuming more so he's feedings can be more spread out. He eats about 32 oz in a day with 2 tbs of Oatmeal in the morning and a small amount of baby food in the evening. Any other moms have this issue? If so is there a way I can get my son to eat more during his feedings??