In my opinion, the solution here is education. The illiteracy of food is a tremendous problem and can't be solved with regulation. Corporations can easily find a loop-hole in regulations that allow them in principle to achieve the same yield. The only way we are going to stop that is by educating consumers. If a vast majority of consumers read labels, research ingredients, and only bought from local farmers, we would force corporations to change from within. I believe this to be true and a model that works, because I live in an area that is currently undergoing this type of change.

We already have education, every food product in American has a clearly designed Nutrition Facts label and there are ongoing public information campaigns on the benefits of healthy eating.

Surely you have noticed that there are also people who systematically attempt to undermine such public education efforts. I think you might at least acknowledge their existence and the existence of advertising that attempts to bypass educational channels to sell crappy foods.