Burn, Baby, Burn: Just How Accurate are Those Calorie Counters?
Posted 11/21/2016 by UHBlog
For those of you trying to control your weight this holiday season, a second sliver of Grandma’s sweet potato pie might mean an extra few minutes on the elliptical. But you may not be scorching as many calories as you think on those machines. That's because calorie counters are notoriously inaccurate, says registered dietitian Lisa Cimperman, MS, RDN, LD.
“Typically, the numbers you see on exercise machines are just rough estimates of how many calories you’re actually burning," she says. "Some studies show these machines may overestimate the number of calories burned by as much as 40 percent. In terms of relying on numbers as an absolute indicator of how many calories you’re burning, I wouldn’t recommend that you do that.”
Part of the problem is that cardio machines use standard formulas to determine the number of calories burned, which doesn't take into account individual measurements.
“Calorie counters are typically based on a 150-pound individual, so if you're 100 pounds, you would have to take two-thirds of that number to get the correct estimated calorie burn,” Cimperman says.
Even machines that let you input your weight don’t necessarily give you accurate numbers, she says. An array of other factors – including age, gender, muscle mass and genetic make-up – all play a role in determining how many calories your body torches per minute.
If you’re simply looking for motivation to get off the couch this holiday season, Cimperman thinks devices that track physical activity, such as a Fitbit, can be helpful, but cautions against putting too much faith in the numbers on the screen.
“Most of these devices are fairly accurate when it comes to activities like walking or running,” she says. “They may be less accurate for other activities, such as biking, elliptical machines or incidental daily activity like house cleaning.”
Mostly, Cimperman advises her patients not to look at these numbers at all.
“People look at the calories they think they burned, and use that as a license to eat more,” she says.
Besides, doing math at the holiday table isn’t fun for anyone.
“You really don’t want to look at food as something you have to punish yourself for afterwards by doing 'x' amount of minutes on the rowing machine or elliptical,” she says.
Of course, you burn no calories at all if your elliptical machine is being used as a clothes hanger. The best way to maintain your weight during the holiday season is to stay active and not overdo the eating.
“I think we always want numbers to quantify things,” says Cimperman, adding that sometimes, the best approach to healthy living is simply having a balanced mental approach.
Lisa Cimperman, MS, RDN, LD is a registered dietitian at University Hospitals Cleveland Medical Center. You can request an appointment with Cimperman or any other health care professional online.