My little girl will turn 9 months in 1 week. For the last 2 months she has eaten 3 meals a day.
She can go about 4 hours between meals - but I basically feed her on demand.
When she drank mainly formula, she drank 28-32 ounces per day. Now that its supplemented with food, its less. Its less than 20 a day.
She eats level 2 fruit for breakfast, a whole package, followed by formula. I give her as much as she will eat - on demand - which is usually 4-6 ounces.
For lunch she eats level 2 veggie - followed by formula in the same style.
For dinner she eats a level 2 meat/dinner - followed by formula in the same manner.
All of these meals are about 4 hours apart - starting when she gets up which is about 9 am.
In between meals I give her the biter biscuits, the banana cookies, and cereal mixed with fruit juice. I give her about 4 tablespoons of cereal. Not too much. Or I make her an egg. Different "snacks" each day.
Then before bed she has a bottle - up to 7 ounces is the most she will take.
Its been working - she is about to move up to the level 3s in a month or so - and the formula will remain the same or go down - on her terms.
Be sure to give him the solid food first and follow it with milk. Otherwise he will fill up on milk and wont want to try the other foods.