Marion Nestle: Oh absolutely.  There’s nothing wrong with vegetarian diets, and there’s nothing wrong with vegan diets.  And people who eat those kinds of diets are often healthier than people who don’t because they’re eating a lot . . .  They’re doing exactly what my advice is.  They’re eating less.  They’re moving more.  They’re eating lots of fruits, vegetables, and whole grains.  And they’re certainly not eating much junk food, so they’re healthier.