David Ludwig, MD: When it comes to fast food, my advice is to just say no. It's remarkable when almost anybody, but especially teenagers, see a movie like Super Size Me,see Morgan Spurlock getting sick, throwing up with fast food, watching what happened to his liver as it filled up with fat, and his cholesterol and his overall health.It's remarkable how quickly people can get turned off to fast food when they really understand the nature of the ingredients in them, which are the ultimate of what we describe as fake food.Um, very little to do with foods that would come from nature, with flavors that are so bland that they have to be masked by indust-, synthetic industrial chemicalsthat have French fry-like or beef-like flavors. So I encourage parents to teach children what fast food really is, to understand how poor a quality it is.And then set clear limits that fast food does not come into the home. Nor do I as a parent take my child to eat fast food.Now if that child ends up going to a fast food restaurant with friends on an occasional basis, that's okay. But that's vastly different than supporting the process and giving it the,uh, the sense of parental approval that children will sense if we uh participate in the process ourselves.