Public activism is great, but it won't sustain.
You need to get people that are interested in health with food to aim for a verification system that food producers will want to be involved in and will eventually seem compulsory simply because everyone is qualified under it in some way.
That system should include major health problems that part of the food may cause, and also perhaps include some of the benefits that individual parts of the food have shown to provide.
The system should also indicate how processed it is, because it seems, in general, that more processed food is less healthy.
It could be a certification, like LEED.
Something else that would help keep customers informed would be an app for a smart phone, such as an Android device. You would take a picture of a barcode of some sort on the food item and it would tell you the information that was outlined above. You could link it to your Google Health profile and use it to keep track of what you're eating and also look out for any interactions between different food items you eat, medicines you're taking, and disabilities they have; you get the picture.