Lots of people use diet and activity trackers to log their food intake and exercise. But it seems to be backfiring.
Lots of people use diet and activity trackers to log their food intake and exercise. After all, there’s an old saying that “you can’t manage what you don’t measure.” And yet it seems to be backfiring.
I get email after email from people using these trackers who can’t understand why they’re not losing weight. They’re entering in every morsel of food and logging every activity. According to their trackers, they should be shedding losing two or three pounds a week. And yet the scale hasn’t budged—or they’ve actually gained weight!
Here’s how these trackers work: You start every day with a certain number of calories to spend. That number is based on your height, weight, age, sex, activity level, and your goals—that is, whether you’re trying to lose, gain, or maintain your current weight.
The Problem with Net Calories
See also: How Many Calories Do I Need?
Calories are subtracted from your balance as you log your meals into the diet tracker over the course of the day. Ideally, you don’t get to zero too early in the day. But if you do, there’s a solution. Let’s say it’s 5 pm and I’m down to my last 400 calories. But wait! I can take an evening run, log it into the app and now I’ve got 840 calories to spend on dinner! How awesome is that?
The general principle here is sound: the more you move, the more you can eat. In practice, however, these “net calorie” calculations are inaccurate and misleading—and they are suckering people into eating too many calories. Let me explain.