Stephen Colbert may be on to something. UCLA Center for Human Nutrition researchers divided study participants into two groups, each of which were fed a nearly identical low-cal diet for 12-weeks. The only difference between the groups was what they were given to eat as an afternoon snack. One group ate 220-calories of pretzels while the other group munched on 240-calories worth of pistachios. Just four weeks into the study, the pistachio group had reduced their BMI by a point, while the pretzel-eating group stayed the same, and their cholesterol and triglyceride levels showed improvements as well.