DooinMeCleanin, I totally agree with you. The rubbish that is spouted about so called "healthy eating" in schools is dangerous.
(dd is 12 - her class had an assignment to record their personal food diary for a week. Those that recorded the lowest number of calories, fat and carbohydrates got the most points and highest grades. Dd is an athlete and trains several times a week. She eats a very healthy balanced diet. She failed her assignment because she had eaten pasta, rice and some red meat. I kid you not.)
That said - it makes sense to tax really unhealthy foods.
I don't know that it would work though - after all, people buy cigarettes.