A national survey by Shape Up America!, a non-profit organization founded by former Surgeon General C. Everett Koop, found that most Americans who have been, or are now, on low- or no-carb diets can't even identify which basic foods are primarily carbs. Two-thirds could not identify tomatoes as primarily carbohydrate and nearly half didn't know that apples were mostly carbs. In general, low- carb dieters were confused about which foods are permitted on their particular plans.