pwa wrote:Vegetarians, by definition, are a group who think about their diet and are willing to give things up. So if you really want to compare the effects of the diet you have to compare them with omnivores who are also thinking about their diet and willing to give things up. That would be an interesting comparison.
Vegetarians in British culture are, by definition, a group who think about their diet.
Some of the studies I linked above have looked included populations of people with various diets. And some have looked at populations of people who are vegetarian for religious reasons, who should represent a better cross section of eating attitudes.