Waking up.... a lot

Ok all you moms... Liam is doing this thing where he wakes up at 3am, 4am, 6am (yes all three) and is so hungry that he is screaming. So since I don't want to wake him up all the way and have him stay up for hours, I give him a bottle of milk.

He has dinner at 5:30ish and gets to bed at 6:30ish. He picks that time to sleep, he is rubbing his eyes, snoozing on our laps, giving clear and unmistakeable tired signs. Even on the times he does stay up later, it does not stop the waking up hungry.

He eats an ok sized dinner. I offer him a good portion of grains, veggies, proteins, and starches. I try to pick things that will stick with him longer; pastas, dense breads, etc. Some nights he eats a lot, other nights not so much but there is no way I can force food into him and I am not going to try. It results in screaming if you even SHOW him a fork when he says he is done.

He has a bottle before bed still, the past two nights I put Pedisure in it instead of milk thinking that stuff might keep him fuller for longer but it does not seem to be working that way.

This is a recent thing, he was sleeping through the night in December or only waking up once around midnight for a bottle.

I am tired. I am so very very tired. I want my sleep. I don't want to be woken up at 3am and 4am and 5 or 6am.

I check the temperature in his room, its fine... not to hot, not too cold. I put a toy in his crib so that if its just that he wakes up bored he has something to play with, but that does no good.

He is not wet or dirty in the diaper department, usually I change him when he first wakes me up at night, just in case, even if he is dry still.

He does not seem to be teething, sick or injured.

I really am confused. For now I have this chalked  up to being a growing and developing phase and hoping it will pass rapidly.

But I am open to ANY ideas or suggestions.... I am so very very sleepy and would love to be able to only get up once a night again.