When was the last time you ate corn? 

If you had asked me yesterday, I would have mentioned the grilled cobs at a recent barbecue or last  month's  theater-popcorn binge during three hours of Batman.

After watching the documentary King Corn last night,  my answer would have to be more thoughtful, because apparently I've eaten a lot more corn, a lot more recently, than I realized.   Corn, it seems, is in our food chain and in our foodstuffs more than I ever imagined.   

King Corn tells the story of college friends Ian Cheney and Curt Ellis, who heard that their generation might be the first in America to have a shorter life span than the one before them. Eyeing nutrition as a probable cause, Ian and Curt examine their own diets. An isotopic hair analysis reveals that over 50% of the filmakers' diet is derived from corn.

This discovery leads the pair to Iowa where in 2005 they grow one acre of corn and follow it from planting through distribution, attempting to learn what goes into the corn, where the corn goes, and how it ends up back on their plates and in their hair.

Their journey is told through footage of their adventure (including  a hilarious attempt to make homemade high-fructose corn syrup ), interviews with the farmers that assist them, and other field experts, including nutrition luminary Walter Willett, MD , and writer Michael Pollan. A must-see for anyone interested in what goes in their food, King Corn is engaging, entertaining and thought provoking. It's already out on DVD -  check your local library or video outlet.