If you eat something and no one sees you eat it, it has no calories. If you drink a diet coke with a candy bar, the calories in the candy bar are cancelled out by the diet coke. When you eat with someone else, calories don't count if you don't eat more than they do. If you fatten up everyone else around you, then you look thinner. Things licked off knives and spoons have no calories if you are in the process of preparing something.
Examples are peanut butter on a knife making a sandwich and ice cream on a spoon making a sundae.
Foods that have the same color have the same number of calories. Foods that are frozen have no calories because calories are units of heat. Examples are ice cream, frozen pies, and Popsicles. If you've got melted chocolate all over your hands, you're eating it too slowly. Eat a chocolate bar before each meal.