A strongly related challenge: even when kids know what choices they should be making, their environment may make the exercise of appropriate choices difficult if not impossible. For example, my wife runs an after-school program for about 100 kids living in the South of Market area in SF. While SoMa is highly gentrified, her kids come from working class and impoverished families. Parents of these kids are incredibly busy, often working 2-3 jobs just to get by. Decent but affordable food is difficult to find, and these parents probably don't feel they have the time or cash to leisurely browse the local Whole Foods in search of a perfect carrot. The corner liquor story is expensive but convenient while offering few healthy choices; other venues are cheap but crappy (while offering few healthy choices). The kids kinda know better... and they still eat really crappy food.
So, beyond AWARENESS of good choices, how might we improve ACCESS to healthy choices within the constraints of people's busy and difficult lives?