According to conventional weight-loss wisdom, dropping a few pounds is a matter of basic math: Burn more calories than you consume and watch the numbers on the scale plummet. But anyone who’s dealt with a stubborn plateau or struggled to maintain a loss knows that in practice, the equation isn’t that simple.
“The old ‘calories in, calories out’ idea is really only a very small piece of the puzzle,” says Lauren Antonucci, RD, CSSD, CDE, CDN, a board-certified sports nutritionist and director of Nutrition Energy in New York City. In addition to diet and exercise, a combination of factors works to regulate your body’s weight, keeping it at a number that’s biologically ideal, according to your genetics, your physiology and your environment. This phenomenon is known as the set point weight theory.