Buzz
When tackling the challenge of weight loss, it’s reassuring to rely on logic and mathematics. For instance, if you've ever tried to figure out how many calories to cut to lose a certain amount of weight, you're probably familiar with the widely known equation: one pound of fat equals 3,500 calories. Unfortunately, this equation is incorrect.
While the equation may be accurate in a theoretical setting, such as in a lab, reducing your intake by 500 calories a day for a week won’t necessarily result in a pound of fat loss. We've discussed this before: trying to perfectly balance calories in versus calories out rarely works as expected.
Enter the new formula, or rather a tool called the Body Weight Planner, developed through research by the National Institutes of Health. Amby Burfoot discusses at Runner's World why we should abandon the old rule and accept the new one:
The main issue with the 500-calorie rule is its assumption that weight loss will proceed in a steady, linear manner,” says mathematician Kevin Hall. “The body doesn’t work that way. It's a dynamic system, where changes in one area always affect others.
What’s more realistic? According to Hall, during the first year of a new weight-loss program, most people who are overweight will shed about half the weight predicted by the 3,500-calorie rule. In other words, within a year, the new rule suggests that 7,000 calories equals one pound. (This calculation varies slightly over shorter or longer periods, and very few people lose weight beyond the 12-month mark.)
Of course, results will differ from person to person.
The new number might initially seem discouraging, but for long-term dieters, it can offer a sense of validation: the science has finally aligned with what your body has been telling you all along. It’s not that you’re not putting in enough effort—it’s that we’ve been working with the wrong formula.
