A new study demonstrates that American adults frequently overestimate the quality of their diet. In a new study presented at the annual meeting of the American Society for Nutrition, researchers surveyed about 9,700 participants, asking them to rate how healthy their regular diet was. They then assessed the actual quality of each participant’s diet. Roughly 85 percent of the participants inaccurately assessed their diet quality, with almost all of them believing their diets were healthier than they actually were.