I would try a smaller meal & see how it goes. I guess after a big sleep it's understandable that their little tummies need a bit of time before a big meal. Emma usually has a play before brekkie too, but she's never been sick if she's eaten sooner (mind you she's more likely to refuse her brekkie if I give it to her too soon). You could give him his brekkie in 2 seperate serves when you have to go out early.