Why food labels are wrong about calories


OK you can trust this food label. But calories? Forget it. Photo credit: Bryan Kennedy

By Richard Wrangham, Harvard University and Rachel Carmody, Harvard University
Food labels seem to provide all the information a thoughtful consumer needs, so counting calories should be simple. But things get tricky because food labels tell only half the story.
A calorie is a measure of usable energy. Food labels say how many calories a food contains. But what they don’t say is that how many calories you actually get out of your food depends on how highly processed it is.