Well, there are actually government guidelines for when these so-called "helpful terms" can be used. Bottom line, "light" may not be as light as you think and "fat-free" doesn't necessarily mean there's no fat.
Based on the FDA guidelines I created the Food Label Decoder below to help you be a more discerning shopper on your next visit the grocery store.
When you pick up something "light-and-healthy" take a closer look to see exactly what you're getting. Light-and-healthy could make you big-and-unhealthy if you're not careful.