john's
may be right. I think more than any government (Canada's has a grainy bias, too), it's actually the docs themselves who will be most reluctant to change for that reason. Most docs seem to be allergic to phrases like "I don't know" and "I might have been wrong."

But I think the main reason there won't be a major behavioral shift anytime soon is that carbs taste great (don't tell me a dinner of pizza, Coke, and chocolate ice cream doesn't appeal to y'all at any level!) and they're addictive and legal. They're hard to give up for most of us and hard to stay off. Long after the medical consensus says to avoid them, we'll be a nation of bread-eaters, I think. Prohibition had a better chance.