If you can't stop digging into your co-worker's jar of mini-Snickers, leave the empty wrappers in plain sight on your desk. People who save this visual reminder of their indulgences eat about half as many candies over the course of a few hours as people who trash the evidence, reveals a study from Cornell University. "We may forget what we've eaten, but the wrappers help keep us honest," says Brian Wansink, Ph.D., executive director of the USDA's Center for Nutrition Policy and Promotion. Food amnesia isn't limited to sweets: Another study found that when bones from a chicken wing meal were cleared, diners underestimated their intake by 50 percent.