A childhood belief about dangerous food

My mother raised us with healthy attitudes toward food, and by the time I was five I knew that you should only eat things such as candy once in a while, but I had never ever heard a food called "bad." However, there were these TV commericals for so-called healthy cookies that said "all the flavor, none of the guilt." I could not figure out why someone would feel guilty for eating, so I concluded there was an entire class of bad (as in evil, not as in unhealthy) foods that it was sinful to eat. But because I'd never heard of any foods in my house being "bad", I also believed that those sinful foods weren't available at the store where we shopped. So every time I saw a store painted a color I didn't like, or kept in a bad state of repair, I thought that was a "bad food store."