Charge 2 calorie counter accuracy

[K_wallace]

Hey guys,

I'm new to exercising regularly. I'm trying to lose weight (5'1" 185 lbs) to become healthier and feel better. I've been working out and watching my diet for about 4 weeks and my boyfriend got me a fitbit charge 2 this weekend to encourage me to keep going. Well, my question is the accuracy of the calories burned on my Fitbit. I had been using a treadmill to track my progress, but today I noticed that my Fitbit had recorded my calories burned as 195 more calories than what the gym treadmill was reading! Can someone please tell me if this is accurate or if I'm doing something wrong?

[Orakkus]

That is kind of what I figured, Foci, but it is nice for it to be confirmed.

I did find out that the Fitbit app does allow you to adjust the Heart Rate Zones which you can use to get a better feel for what you are really burning.

[SunsetRunner]

That may help a bit.  Best approximation I got was changing my weight down from 170 to 100.  It was about a 40% drop in estimated calories burned and a better approximation.

the best I’ve found is this.  Get your RMR tested via a lab (online calls can be off as much as 20% in either direction). From there I add 100 burned per 2000 steps (an estimate based on trial & error).  So RMR @ 1500 and 10000 steps (500 calories) = 2000 per day burned, which seems to work for me.  Without adjusting anything Fitbit would have me at about 3300 (doh.).

again, trial and error and find what works. That’s the best we can do.

[Cindymarie61]

That makes perfect sense to me. I do have a stressful job (IT). I will look
into adjusting HR in FITBIT.

Thank you! Very thankful for everyone's responses. I am learning and
learning is always good.

[Cindymarie61]

i have seen the same results with my husband, although he is not as active
as you!

Thank you for sharing your experiences. Helps me figure out what to try
next.

[Skywolf007]

Dont know about that, today I played a pretty hard badminton game, see screenshot, and i burned 869 calories. That seems to be so much! Im pretty tall and overweight like 20 kilos, but that seems to bee too much calories......

P.S.: fitbit does not have a workout profile for badminton, instead i use tennis. Tested it a couple of times and this was the closest to it. +-5%

[MSow]

One of the more amusing things my fit bit does became apparent earlier today...

I'm a drummer and I kept my Fitbit on this evening during practise. I managed to go from 8000 ish steps to 13000 on about 5 minutes... 😂

[Haki01]

I must say I found a bit annoying calorie burn. I have done 800 steps, 0.58km and burned 980 calories. 

Something is not rightv

[Rich_Laue]

Where these steps going up a hill? How fast where you walking? Are you looking at the record of this walk? 

[Meowmus]

I had that same problem. I set my weight at the beginning not having one of those Fitbit scales and I began to notice my calorie count was up to 30000 calories a day. I went onto the app to see what was up and it told me I weighed 1459.9 pounds so I fixed that and problems gone.

[Anodyne2k]

Just wanted to chime in and note that most treadmills and other equipment for cardio you find in your gym tend to have personal info input for age and weight. Most wont have M/F designations but they do have HR tracking if you use them inserts or a compatible tracker that can be paired with the machine. Fitbit’s calorie tracking does stay on your person and track much more effectively but it’s possible to be very inaccurate here and there. It said I burned 4200 calories on a day I got about 5,000 steps. Compare that to the next day where I burned 4,300 calories on 8,500 steps. 

You should take away at least 5% of your calories burned shown once Fitbit and you’ll be very close. If you really want to be sure you’re not passing your stats, take away closer to 10% since most trackers, when they’re off, tend to be nearly 10% off in their calculations compared to a true metabolic sensor readout. So 4,200 calories = 3,780. Of you’re trying to lose weight it’s inportant to go this route because tracking food intake and calorie output will give you an idea of what you expect to burn and if you’re bloating your output stats you’re going to be disappointed with your actual results (losing .25 lbs per day instead of maybe .35 lbs, which adds up over the course of a month).

[SunsetRunner]

Hello there.

Theres no way you burned 4200 calories with only 5000 steps unless you weigh about 350 + lbs or have a metabolic rate that is about greater than 4 SDs above median.

It would be great, however, if that were possible.  The Fitbit is overestimating calories burned.

there are facilities that can capture your resting metabolic rate and determine oxygen consumption via walking/running on treadmill.  Check one out.  It will allow you to get precise with your calorie needs and show you how inaccurate trackers can be.  Trackers are best used to gauge daily movement, not accurately estimate caloric burn.

[Albanygirl]

I agree that the calorie count is very exaggerated. I tried to ask the question of accuracy thru the Fitbit Q&a but it really diverts you to anything other than an answer. If you look at charts of activity via studies you can only use 1/2 the calories for 10,000 steps, certainly not the 1528 given on my Charger 2. I. Wouldn’t rely on the figures at all. 

[Rich_Laue]

One problem with the calorie count on fitbits is that it uses activity or heart rate, age, weight, size, and a generalized formula. The heart rate helps some in customizing to the individual but it still is somewhat generalized. Currently they do not measure the oxygen consumed which currently is the best portable way to measure calories burnt. 

For me I never look at the calorie count. 

I use the tracker to help monitor my activity, making sure that I'm more active and made my portions smaller .

[SunsetRunner]

Agreed.  Indirect calorimetry is currently the gold standard for measuring oxygen consumption at rest.  Unfortunately, all we can obtain is a point value at rest and estimate daily calories burned from there based on an activity multiplier we guesstimate.

To your point, it will be great when they come out with a measuring device for oxygen consumption.  

[ameslynn]

Don't forget the Fitbit Charge 2 also tracks calories you are burning while sedentary.  Eating, Breathing and all.  This is the reason I enjoy mine so much.  I will say that NO calorie tracker will be 100% accurate but my personal experience (having used others previously) is that this one is very good and much more accurate than my old generic ones.

[Anodyne2k]

Meh, it’s somewhat accurate, if 90% accurate is “accurate”. Plenty of tests have show that the results vary widely compared to actual metabolic observation tools. The old BodyMedia BodyBug was the most accurate calorie measurement tool with over 90% accuracy (averaging something like 94% accurate or better). Unfortunately Jawbone bought them out and doesn’t use the good tech to track. I used the BodyBug for years on and off and wish it were still active.

I just deduct 10% of the calorie burn for the day and use that in my calculations for calorie deficit tracking and weight loss so my expectations are likely spot-on.

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[Trillian01]

Don't forget your Basal Metabolic rate  - the amount of calories /kilojoules  your body needs to maintain itself at rest. 

[shanam]

Well I don't think it OVERstimate the calories. Today I used my Polar with my heart monitor band and at the same time the Fitbit Charge 2. Polar said I burnt 290 calories, while fitbit said 197!! I would trust the polar more since I had my chest band! 

[lkirkes]

I saw that everybody already addressed your basal metabolic rate but I haven't seen anybody talk about the fact that you said you were burning 1800 KCAL per day but you have an intake of 2000 calories per day. In order to  maintain current weight you need to keep your intake of calories the same as calories burned. If you want to lose weight you have to create a deficit so let's say that you take in 2000 calories per day then you need to be burning 2500 (safe) to 3000 (more intense and do this for shorter period of timei). Remember, it takes a deficit of ~3500 calories to lose 1 pound. In other words, if you are consuming 14000 calories/week, you need to burn 17500 to lose 1 pound that week

[SunsetRunner]

True.

But the 3500 calorie per pound of fat loss can be misleading as one gets leaner.  The body can only release (lipolysis) approximately 31 calories of fat per pound of bodyfat to be burned (oxidation) per day.  If someone were 5% bodyfat and 150 lbs, they only have 7.5 lbs of bodyfat.  So that person, can theoretically only lose 232 calories of bodyfat (that was released per day) or 1630 calories per week (less than half a pound).

I can't remember what I wrote before, but caloric expenditure is a dynamic process that is generally formulated as:  Calories Burned = Metabolic Rate (which is best measured by a being in a caloric chamber and/or indirect calorimetry measuring oxygen and CO2 burning) + NEAT (which can be highly variable day to day) + TEF + Exercise.  Metabolic rate tends to decrease (but not by a huge amount when dieting), also NEAT & Exercise calories burned may changed.  So theoretically, a 3500 caloric deficit will result in an approximate 1 lb of fat loss, but this is dependent on dynamic processes that adjust day-to-day, which is why we never see precise losses in fat mass even when calories are controlled and measured tightly.