Charge 2 calories burned too high

[LisannevdL]

I just got my new Charge 2 on saturday so I've not tested it very long, but the calorie count on it seems WAY off. The BMR on it seems correct for my height/weight (1555) but then the calories burned when simply walking a bit are way too high.

Saturday, I went shopping for a few hours that got me around 10k steps in total. I also did a kickboxing workout (268 cals) and went biking (219 cals) and Fitbit calculated 3000 (!!!) calories burned that day. That just can't be right, when my BMR is only 1555 I should've burned 1445 cals with exercise according to Fitbit. Subtract the kickboxing and biking (which is way higher intensity than the walking, calories for that seem correct) from that and that leaves 958 calories burned for walking +/- 10.000 steps.

Has anyone else had this problem? I've Googled for a bit and it seems it was a problem back when the first Charge HR was released too, but I couldn't find a solution. I love the Fitbit and the app but it seems when it takes the constant HR into account when you're not very fit it just overestimates by a WAY too high number. If I ate what Fitbit is telling me I can eat, I'd gain an incredible amount of weight in a very short time.

The numbers I got when I was just counting steps without heart rate (using my phone, before I got my Fitibit) was way closer to the actual number I should be getting for something as easy-going as walking while shopping.

Moderator edit: format

[Mukluk4]

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@Cortic wrote:

Here is some data I have collected over the past 12 weeks since wearing my Charge 2 from the start of January, to showcase its inaccuracy in calories burnt. I am meticulous with my tracking so I an quite confident this data is accurate. All numbers presented are weekly averages.

Week 1 - Burnt 2967 - Ate 2380 - Bodyweight 66.2

Week 2 - Burnt 2675 - Ate 2423 - Bodyweight 65.6

Week 3 - Burnt 2422 - Ate 2544 - Bodyweight 65.5

Week 4 - Burnt 2733 - Ate 2605 - Bodyweight 66.0

Week 5 - Burnt 2767 - Ate 2560 - Bodyweight 66.6

Week 6 - Burnt 2749 - Ate 2505 - Bodyweight 66.5

Week 7 - Burnt 2899 - Ate 2643 - Bodyweight 66.9

Week 8 - Burnt 2777 - Ate 2697 - Bodyweight 66.7

Week 9 - Burnt 2902 - Ate 2698 - Bodyweight 67.0

Week 10 - Burnt 2917 - Ate 2606 - Bodyweight 67.2

Week 11 - Burnt 2818 - Ate 2605 - Bodyweight 67.8

Week 12 - Burnt 2901 - Ate 3040 - Bodyweight 68.0

In every example except the last, I have burnt well over what was consumed and steadily gained weight.The law of thermodynamics says this cannot be so, and therefore, lies an issue with the FitBit and its ability to track daily calories burnt. None of this was logged through selecting "activities" on the fitbit, just wearing it 24/7.

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You are assuming that Out - In = Weight loss.  You also have to account for diet (too much sodium), type of exercise (inflamation).  Weight loss is never linear.

[WilsonFilson]

12 weeks of data is very telling, and it is 100% consistent with my own experience.  Its plain and simple.  Their algorithm vastly overestimates tdee.

[Mukluk4]

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@WilsonFilson wrote:

12 weeks of data is very telling, and it is 100% consistent with my own experience.  Its plain and simple.  Their algorithm vastly overestimates tdee.

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That snapshot of "data" doesn't tell you anything.  For all you know his calories may be coming from Chicken Nuggets and therefore his sodium is through the roof and his lack of weight loss is just excess water or he's just some random dude on a message board just tossing numbers to the wind.

At a minimum to correctly place blame, you need a full dietary and exercise journal, body fat % and standard body measurements from week to week all from a verifiable source (ie. Science)

[WilsonFilson]

12 weeks of water retention????  

So what from your experience tells you that the calorie count is accurate?  I have tracked calories closely over 12 months, and during that time been through 2-3 bulking and cutting phases.  I know right where my maintenance calories are at.  Fitbit tells me I have a TDEE that's about 15-20% higher than my actual TDEE.

[Cortic]

@Mukluk4

In one of my original posts I explained my background but here it is again. I have a Bachelors degree in Health & Physical Education, I am a physique athlete and do in fact meticulously track diet, activity, bf% etc.

To the first point you made, yes, weight loss is never linear, however over time (and 12 weeks is a significant amount of time) a person in a consistent caloric surplus will gain weight, and vice versa for losing weight.

Like you said, its Science.

As for an update to this thread, i'm now in week 4 of using the FitBit with the HR function disabled and I can already see that it is indeed quite accurate at tracking caloric burn based off the user data and steps taken.

[Oregonsunray]

The annoying part about this is that you shouldn't have to disable HR for the calories to be accurate…

Sent from my iPhone

[iangelab]

@Cortic      I am confused, from what I see the only week on your calorie count that you were low enough to lose any weight was week one with a deficit of 4109 calories according to your daily average. (3500 calorie deficit equals 1 pound lost) the rest you were really close maybe 100 -200 calories a day = 700 -1400 calories a week which means if you were absolutely 100% accurate would take you between 3-5 weeks to lose a pound.  and all of this assumes you did not gain ANY muscle mass....  

[Cortic]

@iangelab What's confusing is the data suggesting that despite a consistent deficit, weight increased. Doesn't matter if it was fat, muscle etc you still need to consistently be in a surplus to gain weight, which I was not, yet did.

As an update, I've had the HR function disabled now for a couple of months and it does seem to be fairly accurate at estimating caloric expenditure off steps taken alone.

[IgnacioO]

If someone is burning 3k calories each day, they are also not accounting how much of that is actually gaining muscle. For all we know he is just eating fat, salt and sugar (I mean, seriously, consuming 3k calories a day is probably through an unhealthy dietary habit, unless you are seriously keeping track of it all and planning on achieving that through healthy food).

Another good point to measure is body fat %, body weight hardly paints a picture by itself.

[Rembus]

For the last 10 days or so my Charge HR is recording exorbitant calorie burn. Today it's reading 15171 with less than 6000 steps!

Any ideas why?  Time for an upgrade?  Mine will be two years this August. Any suggestions will be gratefully received. 

[snoot]

Same here. Calories getting higher and higher - also on a Charge HR, getting to it's last legs, I suppose. Certainly not 15k per day, though! Yikes!

I've been worried about mine - I do a LOT of walking so I kind of ignored it but today I did nothing ... my BMR is 1700 and it's telling me I've got a total burn of 3400 calories today ... I'm sorry, FitBit, but where exactly did you get those  other 1700 calories? Was it when I was playing video games? Or maybe when I was laying in bed reading my phone?

It also tells me I had 108 active minutes. I was wandering around a bit in the house, sure, but not 108 minutes worth. I checked out the dashboard - it is a dashboard of LIES. 

I've turned off the HR due to the suggestions in this thread and will see if that helps!

[YBSIU87]

I have found that adjusting the food plan to one of the higher options I.e. kinda hard and harder is a better indicator of what the calorie intake should be

[SizzlingTwizzle]

I found this article that seems relevant.

According to a study by Stanford Medicine this year, the estimated number of calories burned by personal wearable devices can be way off. The study only was done while people were actively exercising on a treadmill/stationary bicycle.

"...none of the seven devices measured energy expenditure accurately, the study found. Even the most accurate device was off by an average of 27 percent. And the least accurate was off by 93 percent."

http://med.stanford.edu/news/all-news/2017/05/fitness-trackers-accurately-measure-heart-rate-but-not...

[lb80]

Interesting. If I'm reading the report properly it seems as though the
FitBit device tested was one of the better ones however calories burnt
estimates can be off by +/- 25%.
--
Lee

[Oregonsunray]

I wish I could vote x10 like.  This is vindication. Fitbit should work on their algorithms but now I see that it's not like other wearables are better...

As for me, I leave HR setting "ON" (part of the purpose of purchasing the device was to give me that information), and  just completely disregard the calorie expenditure. Instead, I set my calorie goal based on my lean body mass, less the mathematical equivalent to 1 pound per week weight loss. That is my calorie intake target.  It's aggressive because I have a lot to lose, but I think the same could be done without the intended calorie deficit,

e.g. Set your calorie target independent of what your wearable reports as your expenditure.

Thanks again for this article – awesome!

[vin42077]

I agree with you Lisa and Richard! I, too, just recently started using the fitbit and the amount of calories it says I'm burning each day (mostly from my step count) seems incredibly high. I realize that I burn calories with minimal activity or even at rest (BMR), but I just can't grasp the 2000+ calories a day it says I'm burning just from walking and minimal activity- not including my exercises. And ever since syncing it with the myfitness pal app, the calorie adjustment is completely throwing me for a loop because of this. For instance, yesterday, per fitbit, I burned a total of 3,439 calories with 207 calories burned in exercise on the stationary bike (which is certainly not accurate, because my bike has a heart rate sensor and its own algorithm to calculate my calories burned and it was 396 for my 30 minutes. So even if the bike isn't a true calculation I'm sure it's not off by 189 calories! - many people have said it does not do well at accurately calculating stationary bike exercises though). But what I'm getting at is if we take the 207 calories out and just leave the rest, it says I burned 3232 from the minimal activity I did during the rest of the day + my BMR. I don't see how that can be. And when all this data syncs to my myfitness app as a calorie adjustment, myfitness shows a total of 1,163 calories burned and basically tells me that even after my calorie intake with food is completed for the day I still have well over a thousand calories remaining that I can intake per my goal. Ummm really?!  Oh and then when I complete my diary for the day in myfitness it says 'if everyday were like today I'd weigh ... in 5 weeks" -let's just say it says way under the weight of what is actually true because of this adjustment per what fitbit calculates. If I were to intake those remaining calories it says I have left each day I'd be gaining sooo much weight! So yea... kinda not cool for people trying to lose weight that are trusting what fitbit says about how many calories they're burning. Where's that guy that did the 'Super Size Me' movie? I need him to test this out by mimicking my day to day for 5 weeks eating all of the remaining calories I have left each day to see if weight goes down like it should per how I've entered my goal or if he puts on weight. I'm willing to bet on the latter!

[ReallyAwesome]

Reading this thread with great interest. Googled "fitbit calories accurate". My charge 2, which I have had for a week with hr enabled, shows on average 3300 kcals/day on 12k steps. I'm 88 kg, 196 cm so my BMR should be around 2000. Google fit with my phone's pedometer shows around 2350/day so that's almost 1000 kcals less. Also, my resting heart rate is anywhere between 65 and 75 according to fitbit, but I often have 85 bpm just sitting, after coffee and perhaps a bit mentally stressed, so i expected that fitbit overestimated my cals and that my weight would be unchanged or increased. (going with 700 kcal deficit/day according to fitbit). 

Surprisingly, I had a weight loss GREATER than what fitbit cals predicted. The fault could of course be on my part, but I've been pretty meticulous about measuring and registering my cals (makes my girlfriend mad, lol). It's just one week, with a firmware update in the middle of it, but hopefully the cals are more correct now, perhaps they changed their formulas. If not, perhaps it's just accurate for the average person and I happen to be average. Here's hoping next week will be the same... 

[Vick_M]

Lisa, 

people have reaponded to you but you keep glossing over it. Your calories burned isn't JUST BMR + Exercise. Depending on how much you're standing in a day, you're burning additional calories. You're also doing a bunch of walking that is in short spurts and doesn't register as exercise but still burns your calories above your BMR. It's not unusual for my Fitbit to say I'm burning 4,000-5,000 calories in a day. My goal is 3,500 and I meet that 90% of the time, and only exercise 4-5 times a week. 

I recently bought my Charge2 two weeks ago and have lost 5 pounds already. I started reading people claimed the calories burned were way overestimated so as a test I started eating 2,800-3,500 calories a day over the past several days and I'm still LOSING weight, albeit not as fast. 

[Vick_M]

So in other words, your BMR is what you'd burn if you stayed in bed all day. Walking, eating, getting dressed, standing up, etc, all of those aren't "exercise" but burn calories. BMR + Exercise isn't anywhere close to a realistic measure of what you're burning. 

[mollymia]

has anybody notice their charge 2 still tracking steps (or arm movements as steps) AND giving calories expenditure to them while you're already on exercise tracking mode?