Since the promotion of low-fat diets and production of reduced-fat or fat-free versions of foods began in the late 1970s and early 1980s, Americans have become overweight and obese at epidemic levels: In 1980, approximately 14% of the U.S. population was obese; now, 40% of U.S. women and 35% of U.S. men are obese, accounting for half of the more than two-thirds of U.S. adults who are overweight or obese. This national weight management crisis is likely attributable to several factors, but among…