I also take ritalin, and i have read that you can't take the immediate release with food or drink and hour before or after taking it. The sr and er versions of the drug can be taken with food.

Diet though plays a big role in how effective ritalin will be. Eating food or drink that are acidic or highly acidic will cause you to eliminate the drug faster. Having a more alkaline diet will prevent this. So a combination of some acidic foods combined with mostly alkaline is the best way to eat while taking drugs like ritalin.