Bijal Trivedi, “The Calorie Delusion: Why Food Labels Are Wrong,” New Scientist, July 15, 2009

This article explores how the method of estimating the calories in food, developed in the late 19th century, may provide misleading information on the amount of energy people actually get from a food. The calorie counts are calculated by burning small samples of food, and science writer Bijal Trivedi observes, “Nutritionists are well aware that our bodies don’t incinerate food, they digest it. And digestion— from chewing food to moving it through the gut and chemically breaking it down along the way—takes a different amount of energy for different foods.”

Trivedi compares the nutrients in a health-food bar and a chocolate brownie and discusses research showing that more highly refined, cooked and softer ingredients tend to be absorbed more readily when eaten, thus contributing higher actual caloric intake than raw or chewy foods. Despite the acknowledged inaccuracies in calorie counts, most nutritionists have apparently decided that the measuring system should not be changed because “the problems and burdens ensuing from such a change would appear to outweigh by far the benefits.”