When we talk about eating and exercise, we often talk in terms of calories. Menus at chain restaurants quote the number of calories in every dish. Treadmills tell you the number of calories burned. Dieters count calories religiously at each meal; other people joyfully declare that calories don’t count on the weekend.
But what exactly is a calorie, anyway?
“The calorie is nothing more than a measurement, just like inches or kilowatts,” says Lauri Wright, assistant professor of nutrition and dietetics at the University of North Florida and spokesperson for the Academy of Nutrition and Dietetics. “It just represents how much energy is contained in the food or how much energy is used by the body.”