Here is an idea.  
Most cities and counties in the US are concerned because a growing number of their residents are overweight or obese.  The cost to society in lost productivity and medical care is sometimes staggering. A growing body of evidence suggests that the biggest contributor to this national rise in obesity is the abundance of energy dense, cheap, nutrient poor, high fat, high sugar, processed foods.  Another factor is the heavy marketing and promotion of these foods.
SO - maybe we should stop advertising them or the places where they are sold on our county and city buses! 
(Today I saw an ad for a $4.99 Steak and Shake special on the back of the bus that passed me as I rode my bicycle home from school.)