On cooking shows, when the host/hostess of the show takes food out of the oven, or shows the final version of a cake, roast, appetizers, whatever, how much of that is actually prepared by the star themselves? Do they really cook or prepare all of the food on the show?

I know assistants do the chopping, and other tasks like that. I mean when Paula Deen has a cake that is iced, did she ice it? When Rachel Ray has a platter of appetizers, did she make them? When you see a host take cookies out of the oven, did that host make the cookies?