All great replies. We had to up the milk following his gastro as he dropped a bit of weight, and then was ravenous after. His hunger affected his sleep and he went from sleeping through to waking three to four times a night. I think he's still playing catch-up with his milk so I'm not keen to reduce his milk yet until back to normal weight.
Will try the solids before milk for one meal a day and see how we go. Will keep you all up to date... thanks!