No, but primarily because I'm a diabetic and fasting typically isn't a good idea.
What I do instead is plan out preparation rituals that will support the intent of the ceremony to be conducted. For instance, if it's a ceremony to honor a major holiday, such as Mabon then small snacks or dishes that include applies (apple muffins, cooked apples, apple pie, stuffed apples etc.) can be part of the preparation and still supports the essence of the holiday.
Another example, many work with the energies of the full moon and honor the night by honoring the name of the moon. For instance some work with a list of names where the full moon of July is known as the Buck moon (moose & deer). Some people will hold a feast that serve a dish made from one of these.
I agree with Seachain Aroon though, it does depend on what the ritual or spell work is for. It also depends on the individual person and what their health condition will allow or not. Again, it wouldn't be wise for diabetic to fast all day unless they strictly monitor their sugar level. You don't want to be passing out or falling into a diabetic coma while you're dancing skyclad around a bonfire. ;-) Ouch.