This is one of those questions for wedding photographers that many couples don't see as relevant until they really think about the work that documentary wedding photographers achieve.
The short answer is yes. With full-day coverage, we entirely concentrate on producing beautiful wedding photographs, we have little time to think about sourcing, cooking, or chilling food and therefore need feeding and watering throughout the day.
We ask that we have a hot meal at the beginning of the wedding breakfast, allowing us time to digest before springing back to work!