There will always be some dispute over the precise components of a healthy diet, but fruits and vegetables have established themselves as essential ingredients on most people's lists. But then why, when we all have a general idea of what's good for us, do we tend to walk past the fresh produce isle and load up on processed and less healthy foods instead? The problem is marketing. Junk food purveyors have perfected the subtle science of attracting attention and desire from their customers, while fresh food usually just sits passively on the shelf, deprived of any fancy packaging or superhero endorser.

Now, an enterprising research team has sought to find a solution in the problem itself: by borrowing some of the promotional tricks of the snack and soda industries. They placed happy emoticons next to healthier food options in school cafeterias and found, unsurprisingly, that the kids responded by replacing their chocolate milk with a plain variety and adding more veggies to their meals. Just because of some green smiley faces. When the stakes were raised with the addition of a small prize for choosing a full "Power Plate" of healthful foods, the students again reacted positively and increased their good food choices.