I've done it before. It was for a nut allergy. Mom had to bring the child's food. If mom forgot I didn't accept the child into daycare. As I didn't feel comfortable to just feed her "whatever". She had to leave with the child, go home get the food then come back. It happened twice but she understood why I was uncomfortable and was fine with it. I didn't have any other problems. I put in my contract that if food was forgotten care would be unavailable till food was brought. Obviously gluten is less a worry then nuts but I don't take a chance when it comes to allergies.