Think everyone around the world eats meat-centered diets or that you can't get enough protein being a vegetarian? The American Dietetic Association has handy paper you can print that dispells myths about vegetarian eating. You can find it here.
They did a nice job of putting this information together. I really appreciate how they dispell the myth that most people in the world eat a meat-centered diet, as they do in America.
Print it and use it as needed.