Written By: Christina Schoerner, MS, RDN

Women-Walking-300x198 Is My FitBit Making Me Fat?“OH GOSH! I HOPE NOT,” I thought as I read a recent article discussed on the Today Show.

If you’ve met me you most likely had THE conversation with me. THE conversation, that is, about my FitBit. I am slightly obsessed.  I have owned my FitBit for almost two years. Just like many owners of tracking devices, my daily goal is 10,000 steps. Have I met this goal every day? Gosh no! But I truly believe that it has spurred me to be more active in my daily living. Whether it is that I only got 3,400 steps one day that boosts me to step up my game or seeing a number like 8,500 steps that sends me out for an evening stroll; My FitBit motivates me. A study from Stanford in 2007 discovered that people who wore a pedometer walked approximately 2,100 more steps a day than those who did not. So the odds seem in my favor.

What can a pedometer offer? All are created differently. In general, activity trackers can track daily steps, distance, and calories burned (based off your provided height and weight). Some trackers sync to your smart phone, calorie-counting apps (like MyFitnessPal) and allow you to set personal goals along the way. And, some even track how well you sleep and allow you to challenge and cheer on your friends.

So is my FitBit making me fat? I don’t think so. However for some this seems to be the case. Owners of different tracking devices have blogged, complained, and reported these simple facts: they have increased their physical activity, eaten the recommended calories calculated by their device, and they have gained weight.

As a dietitian who understands the tediousness of counting calories and increasing exercise to lose weight, it dawned on me how the general public could be taking their FitBit calorie numbers too seriously.  (“Seriously? but I just dropped $100 on this thing,” you say.) Yes I repeat: Many are taking the calories calculated by their device too literally. Although we live in an age of wonderful technology, nothing can be that accurate… well, not yet, anyway.

After years of education and experience in nutrition, I disregard the computer-calculated calories that my FitBit displays. As much as we want to make weight loss a mathematical equation of [Calories in < Calories out = weight loss], it is not that simple. There are many other factors that affect this equation (sleep, stress, genes, metabolism, smoking, medications, and quality of food in diet….just to name a few). These other factors are exactly what is making your very accurate step-tracking device a not so accurate calorie counting device.

What does this mean for me? Keep stepping. Continue reaching or even exceeding your daily step goal. Be active. Encourage your friends and family to choose activities that get you moving. Don’t let counting steps replace your current exercise routine. Many Americans only count on their 30-45 min workout session a day. In reality, the rest of the day their body is sedentary. Research has found that being active in shorter time periods frequently throughout the day can be more beneficial than your  hard-core gym class. Instead let your FitBit be a motivator to take the stairs, walk to work, park in the furthest parking spot on your next errand, and walk around the block at your lunch hour or after dinner.

What about your calories? I recommend meeting with a registered dietitian/nutritionist to discuss how to best meet your weight loss goals. See if a dietitian or MD in your area offers RMR testing (resting metabolic rate) through indirect calorimetry (a technique that provides an accurate estimate of your calorie needs by measuring CO2 production and O2 consumption at a resting state). Until then…. just because you walk a little bit more one day does not mean you need to replace those calories lost! For weight loss you want to create a deficit. A good baseline on how many calories your body needs a day can be calculated by plugging your information into the following RMR equation:

Men: 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years) = RMR
Women: 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)= RMR

After you insert your personal numbers and calculate your RMR, multiply your total number by an activity factor:

Sedentary: BMR x 1.2 Light active: BMR x 1.375 Moderately active: BMR x 1.55 Very active: BMR x 1.725

To lose weight: Subtract 500 calories from your new number.

This is a rough estimate of what your caloric needs are. I advise using a lower activity level, as many of us believe we are burning a lot more calories than we really are.

Instead of following the calorie level on your FitBit or other devise, set up an account with MyFitness Pal. Set your calorie goals to the number you calculated above. Remember, just because you went on that three mile run doesn’t mean you need to reward yourself. Calories eaten tend to add up a lot faster than calories burned!

Is a FitBit for you? If you are looking for a little help in the motivation department or are ready to shed some excess weight, a fun activity-tracking device can benefit you. So keep track of those steps but leave aside tracking the calories burned.

Remember: Any activity that you do today and in the future that you didn’t do yesterday is going to benefit your whole well-being and health!

Now, get to steppin’! I am right behind you.