I provide all food. When I first started and I just had 1 child, the mom would provide food. Her child was 1 year old, and she would send him a jar of stage 1 apples for the whole day.
But, once I became licensed I took care of all food. To me, it just makes sense. Plus, I know the kids are heating healthy and there's no fighting if someone has a food that the others want.
However, I don't cater to special diets. I have a child whose mom doesn't want him eating dairy or citrusy foods, so she brings substitutes on the days we have those.