Archive for September, 2010

Why Calorie Calculators Aren’t Always Accurate

September 24th, 2010 No comments

Be skeptical of online health and fitness tests (or, Don't Count on Calorie Counters)
When browsing through most health and fitness websites, you’re sure to come across a variety of calculator tools that will determine everything from your body mass index, to ideal body weight and caloric needs. It’s fun to input your stats and see what comes out.

But if you’re relying on these calculators for anything more than an anecdotal number, you might end up following some very bad advice.

Not all calculator tools are the same
Not all calorie, BMI or ideal body weight calculators use the same formula to come up with their numbers, so one can be very different from the next. As well, some calculators take more variables into account than others. But just because a website’s calculator is more in-depth doesn’t make it any more accurate.

Don’t blindly trust the results
Know your body. If something that’s recommended sounds too extreme get a second opinion from your doctor, which you should be doing anyways if you’re starting a weight loss program. At the very least you should see what other calculators come up with, because as I’ve found firsthand no two will be the same.

The advice you get can vary widely
I checked out a few calculators to find out my BMI and my daily caloric needs to maintain my current weight. It’s a good thing I didn’t seek out this kind of advice when I was starting my fitness journey.

In order to maintain my current weight with my moderate activity level (I can’t be considered very active because of my sedentary job and the fact that I don’t exercise every day) they tell me I need to consume either 1,300, 1,815 or 1,909 calories per day. That’s a pretty big difference. Trying to maintain my weight by following the lower guideline and I would end up losing about a pound of week (if the higher one was actually correct).

What makes it worse is I doubt my calorie intake falls anywhere within that range. If I do a quick total of what I eat in one day I come up with a number closer to 2,000. Only one calorie calculator I used hit that target.

As for my basal metabolic rate (BMR) the number that comes up most often is around 1,300, which means I need to consume that many calories just so my vital organs can function. The Discovery Health site’s calculator agrees so I assume it’s a safe number.

Some results can be dangerous
Now here’s where it gets sketchy. Many of these calculators are used for the purpose of deciding how many calories you need to eat to lose weight. But since they can’t even get the numbers right when it comes to maintaining weight, imagine how far off they could be when it comes to losing weight. When I put in the weight I was at a year ago they calculated that I’d need to eat between 1,100 and 1,466 to lose weight. Plus a number of them mentioned adding exercise without changing caloric intake.

Well, I did lose weight, and I did it by eating better, doing cardio and strength training but there’s no way I would have starved myself like these tools suggested. My one pound or less a week came off the healthy way, which is why I’m feeling pretty good about my chances of maintaining it. Listening to bad advice could cause your body to work against you and conserve instead of expend calories, making the weight loss process more difficult than it has to be.