by Eliza Barclay Jaunuary 26, 2011 NPR      Fresh produce piled high at a farmers' market. We've heard it before: most Americans have a pretty big problem with food. We eat too much of it, and a lot of the stuff we eat is junk. It's everywhere we turn, tempting and distracting us. Our overindulgence is even altering our brains.   But Todd Essig, a psychoanalyst at the William Alanson Whit…