Education costs money, and you're fighting a culture of profit.
So long as it's profitable for vendors to increase profits they'll keep selling larger and larger portions, no matter how unhealthy it is. This is how the American public has been taught how to eat - by corporations with a profit motive.
This is not an assault on your rights. Well ok, it is. It's really intended to fight unscrupulous sugarwater vendors. At least it's something. They started with cigarettes many years ago and decades later it's had some effect.