FitBit Calorie Burn Over-exaggerated

afhowell757
afhowell757 Posts: 8 Member
edited November 14 in Social Groups
I am a new Fitbit user (Charge HR), only having it for 5 days now and I WAS super excited. I visited my weight loss doctor today and told her all about it. She crushed my dreams saying that Fitbit devices tend to over-exaggerate the calorie burns. She put it that Fitbit is designed for athletes with lower body fat percentages (muscles burns more calories), therefore will have a higher burn that a person that's obese. Even with the heart rate monitor, it doesn't account for your body composition and can give a false readings. Therefore, the device will tell you you are burning more than what you really are. I looked online for her claims, but found nothing. At this moment, I feel like I may have wasted my money. Any input on this? Thanks!
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Replies

  • shadow2soul
    shadow2soul Posts: 7,692 Member
    The only way to know is to use it for 4-6 weeks and compare expected loss to what actually happened (you have to be pretty accurate with your logging during this time as well).

    As for me, it slightly underestimates. The HR version (I have surge currently) seems to have a very small error margin compared to the previous versions I've used which underestimated by several hundred calories for me. I was over 200lbs when I started using Fitbit so I was both not an athlete and had a high BF%.

    It's just an estimate and should be treated as such. Work with it for a few weeks then adjust up or down as needed. For some people it will overestimate. For some it will underestimate. For some it will be perfect. You won't know however until you try it. Just like the online calculators people use to come up with a calorie deficit. It's trial and error.
  • shadow2soul
    shadow2soul Posts: 7,692 Member
    Oh and to make the comparison easier. There is a 30 Day average Burn and 30 Day Average Intake on your Fitbit profile page.

    30 Day Avg Burn - 30 Day Avg Intake = Avg Daily deficit
    Avg Daily Deficit * 30 = Total 30 Day Deficit
    Total 30 Day Deficit/3500 = Expected Loss
  • editorgrrl
    editorgrrl Posts: 7,060 Member
    Trust your Filtbit for several weeks, then reevaluate your progress. I lost the weight and have maintained for 8 months, so by definition my Fitbit burn = TDEE (total daily energy expenditure).

    And trust me, I'm no athlete!
  • williams969
    williams969 Posts: 2,528 Member
    I've had a Fitbit for over 8 months now (started with the Zip, now have the Charge HR). They both UNDERestimate my burn by ~200 calories/day (based off eating every calorie allotted to me at maintenance level, but still losing weight at around 1/2lb/week).

    And I'm surely no athlete of any sort--far from it, lol. I'm just an avid walker and calisthenics fan girl.
  • Kidominos
    Kidominos Posts: 1,249 Member
    I have had a Fitbit One for over a year now (linked to MFP the entire time). I have lost 57 lbs last year by trusting my Fitbit total calorie burn (TDEE) in conjunction with a calorie deficit on MFP. I am now in maintenance and using my Fitbit TDEE as my calorie goal to eat each day and I am holding steady in maintenance. My Fitbit One has been very accurate for me. I clip it to my pants pocket most of the time but also on my bra if I don't have pockets to clip it to.
  • 7lenny7
    7lenny7 Posts: 3,498 Member
    I wouldn't worry about supposed inaccuracies. If the Fitbit motivates you to move, it's a great tool. I've only had mine for 12 days so I can't say if it over or under estimates calorie burn, but I can say that it has motivated to both get more exercise, and eat less (and better).

    Use it, trust it, and see how your body reacts after a month or two. Does your results match what you expected based on the actual numbers from FB & MFP? If you're not losing as much as you expected, don't eat all the calories in your budget every day. Leave 100, 200 or whatever. I do that anyway so that when I go way over (party, night out, whatever), I'm covered.

    I'm technically considered obese (I would never have guessed it) and putting my trust in Fitbit & MFP and their calorie logging, I've lost 5 pounds in 10 days, so I'm already seeing results. But, if takes me 40 weeks instead of 35 weeks to reach my goal because Fitbit's numbers are a little off, I'm fine with that.

    You're on the right path, even if that path may be a little shorter or longer than you expect. As long as you keep moving towards your goal, you'll get there.
  • NancyN795
    NancyN795 Posts: 1,134 Member
    Maybe you can prove your doctor wrong. Take the advice given here and log your food very accurately (use a good digital food scale and weigh everything) for a month or more. See what your results are.

    I am obese (just over 200lbs, at 5'1"), I have a Charge HR. I HAVE been exercising daily for just over 2 years, so I'm no athlete, but I'm a lot fitter than I used to be.

    Up until recently, I didn't log my food carefully. But, I'd stopped losing and had gained back a little, so I decided I needed to up my game. So, for just over 3 weeks now, I've been trusting my FitBit and logging accurately. In the last 3 weeks, my calorie deficit, according to FitBit, has been 11,306 calories. My weight loss, in those 3 weeks, has been 3.2 lbs. So, very, very close to 3500 calories/lb, just as predicted. I need to give it more time, but at this point, I believe my FitBit is quite accurate. It really motivates me to log my food accurately, because I am confident that I know how many calories I'm burning.

    Even if it is somewhat off, if you follow the advice and track things carefully for a month or two then you'll be able to figure out how far off it is and just apply an offset. (For instance, if you track for 4 weeks and your FitBit says you should have lost 4 lbs but you only lost 3, then it is overestimating by an average of 125 calories per day. So, you'd make sure you always had at least 125 calories left to eat at the end of the day.)

  • NancyN795
    NancyN795 Posts: 1,134 Member
    Oh yeah, one more thing....

    Shame on your doctor!

    You're really trying to work on your health and weight and she "crushed your dreams"!

    Even if the FitBit didn't work at all (not true), that's no way to motivate someone.

    Maybe you need a different doctor.
  • kuranda10
    kuranda10 Posts: 593 Member
    I would say mine underestimates. I have the Charge HR and I upgraded from the One that I had for two years. The HR portion does get it's data from your veins, so if you are VERY obese, that part may be off, but since there is an XL size available, I'm thinking the company may have accounted for this. The steps and activity data wouldn't be affected by your weight.

    I would also have said that the FitBits are exactly made for the more average person and that athlete types would have more problems with them given they are doing far more exercise that FitBit wasn't really made to track.

    They aren't perfect, but they get you to move.
  • beachmom01
    beachmom01 Posts: 7 Member
    I have been using my fitbit flex for a year and it is quite accurate. You have to log your food accurately (use a food scale), but if you do, you can trust your fitbit. I have mine set to sendentary and I eat back my adjustments. Most days that is an additonal 650-1000 calories and I lose pretty close to predicted. Some weeks a little more, some weeks a little less, but the trend is always downward. I trust it for my TDEE way more than any online calculator and it adjusts on a daily basis depending on my activity.
  • Robbnva
    Robbnva Posts: 590 Member
    NancyN795 wrote: »
    Oh yeah, one more thing....

    Shame on your doctor!

    You're really trying to work on your health and weight and she "crushed your dreams"!

    Even if the FitBit didn't work at all (not true), that's no way to motivate someone.

    Maybe you need a different doctor.

    This

    IMO mine over estimates a little, so don't eat all of your exercise calories and you'll be ok
  • heybales
    heybales Posts: 18,842 Member
    It's going to tend to under-estimate in general for daily life.

    Because all non-moving time is given sleeping level calorie burn - BMR.
    But awake you burn more - RMR.
    Standing not moving you burn more.
    Digesting & processing food you burn more, about 10% of calories eaten.
    All of that is unaccounted for.

    As far as the HRM calorie burn for you - test it. See how far off it might be.
    And be aware the HRm calorie burn is only used during exercise, not daily life.

    http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is

  • Kidominos
    Kidominos Posts: 1,249 Member
    heybales wrote: »
    It's going to tend to under-estimate in general for daily life.

    Because all non-moving time is given sleeping level calorie burn - BMR.
    But awake you burn more - RMR.
    Standing not moving you burn more.
    Digesting & processing food you burn more, about 10% of calories eaten.
    All of that is unaccounted for.

    As far as the HRM calorie burn for you - test it. See how far off it might be.
    And be aware the HRm calorie burn is only used during exercise, not daily life.

    http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is

    Fitbit does include your BMR. Go to the Fitbit website and click on "log" at the top of the page and then activities - calories burned. It will show how many calories you burn while sleeping in 5 minute intervals. For example mine shows I burn 4.2 calories every 5 minutes while doing nothing.

    4.2 X 12 = 50.40 calories burned per hour

    50.40 X 24 (hours) = 1,209.6

    Now go to a site that will calculate your BMR. I just end used MFP (under apps). MFP shows my BMR as 1,218. Fitbit is only under by 8 calories. If Fitbit did not include BMR and I added those 1,210 calories back in to be available to eat I would be gaining weight, and rather quickly if I tried to eat back my BMR each day. (3,500 extra calories = 1 lb weight gain).

  • ILiftHeavyAcrylics
    ILiftHeavyAcrylics Posts: 27,732 Member
    I have the flex so no HRM, but mine underestimates a bit. It's actually pretty perfect-- it allows me enough wiggle room to occasionally go over without worrying about having to make it up.

    It's true that none of these devices are completely 100% accurate. If you use it for a few weeks and you're not getting the desired results then sure, you need to reevaluate. I see threads occasionally where someone isn't losing weight and they just won't believe that their calorie burn estimates might be the problem (because HRM!). But for many people fitbit is accurate enough for weight loss, maintenance, or bulking. So I'd at least give it a try.
  • NancyN795
    NancyN795 Posts: 1,134 Member
    Kidominos wrote: »
    Fitbit does include your BMR.

    Heybales knows that. What he was saying is that FitBit can't differentiate - as far as calorie burn is concerned - between sleeping, sitting still, standing still, etc. It only allots BMR calorie burn if you're not moving much when you're actually burning at least a little bit more since you're awake, probably at least sitting, maybe standing, maybe digesting food, all of which burn calories at a higher rate than sleeping.

  • Kidominos
    Kidominos Posts: 1,249 Member
    edited March 2015
    LOL..

    Many people are brand new to owning a Fitbit so when someone writes something (like BMR is not accounted for) they are going to think he meant what he wrote.

    Bottom line is that no device is 100% accurate. Many of us have been using Fitbit's for a long time now. I don't know about the new styles with the HMR but my One has been very accurate.

    ETA: spelling
  • cariie
    cariie Posts: 6 Member
    nothing is perfect. If you are expecting it to give you 110% accurate results, you will be dissapointed. What fitbit gives me is awareness. Information. Motivation. When i havent walked enough, it tells me. Logging my sleep, my water, my food etc helps me to really start to udnerstand my intake and outtake and make better choices.
  • akdetweiler
    akdetweiler Posts: 38 Member
    I have been wearing the charge HR for almost two weeks and have lost 2 lbs because of the data it provides me. I used to wear a BodyMedia Fit armband and have found the FitBit to be far more accurate. Just try it!!! If you lose weight in the first two-four weeks then you know you are on the right track, if not, then just start increasing your calorie deficit until you start losing. I find it to be a great motivator!! Good luck!
  • shadow2soul
    shadow2soul Posts: 7,692 Member
    Kidominos wrote: »
    LOL..

    Many people are brand new to owning a Fitbit so when someone writes something (like BMR is not accounted for) they are going to think he meant what he wrote.

    Bottom line is that no device is 100% accurate. Many of us have been using Fitbit's for a long time now. I don't know about the new styles with the HMR but my One has been very accurate.

    ETA: spelling

    But that's not what he wrote. He said it can't tell the difference between BMR and RMR so it just gives you BMR.
  • kmbweber2014
    kmbweber2014 Posts: 680 Member
    I've consistently lost with my Charge HR. I think it underestimates, I know my flex did. It also just motivates me to get going. I do challenges with people and it makes it even more fun.
  • Kidominos
    Kidominos Posts: 1,249 Member
    Kidominos wrote: »
    LOL..

    Many people are brand new to owning a Fitbit so when someone writes something (like BMR is not accounted for) they are going to think he meant what he wrote.

    Bottom line is that no device is 100% accurate. Many of us have been using Fitbit's for a long time now. I don't know about the new styles with the HMR but my One has been very accurate.

    ETA: spelling

    But that's not what he wrote. He said it can't tell the difference between BMR and RMR so it just gives you BMR.

    Ok, so where did he write "it can't tell the difference between BMR and RMR so it just gives you RMR"? I just see where he listed multiple statements and then finished up the paragraph with "All of that is unaccounted for."

    I think we all are in agreement. I just don't want someone who is trying to learn what and how Fitbit works to get accurate info so I clarified.

    Fitbit has been a great tool for me and helped me lose 57 lbs and now to maintain. My Fitbit TDEE is accurate for me.
  • kikih64
    kikih64 Posts: 349 Member
    I can't exactly vouch for accuracy, but I've been at maintenance for over a year and I have my calories set at what my Fitbit tells me is my average burn. I agree with other posters - if it motivates you to move more and you're hitting goals you wouldn't have hit otherwise then I think it's a good tool. Good luck.
  • WSLady
    WSLady Posts: 4 Member
    Your posts are SO encouraging. I agree with the philosophy that my Fitbit raises my awareness that I better get out of my computer chair and put in walking time. I know that having used it for about two months - I feel better and coupled with MFP meal plan I have lost over 10 lbs without a lot of stress (down from the 200 lbs). I will keep using the two systems and push onward to my goal. I am 5'4", 72, diabetic, not an athlete, but a primary caregiver for three family members with serious health conditions. So, I have to stay active and in as good health as possible. Thanks for the encouragements!!!
  • shadow2soul
    shadow2soul Posts: 7,692 Member
    Kidominos wrote: »
    Kidominos wrote: »
    LOL..

    Many people are brand new to owning a Fitbit so when someone writes something (like BMR is not accounted for) they are going to think he meant what he wrote.

    Bottom line is that no device is 100% accurate. Many of us have been using Fitbit's for a long time now. I don't know about the new styles with the HMR but my One has been very accurate.

    ETA: spelling

    But that's not what he wrote. He said it can't tell the difference between BMR and RMR so it just gives you BMR.

    Ok, so where did he write "it can't tell the difference between BMR and RMR so it just gives you RMR"? I just see where he listed multiple statements and then finished up the paragraph with "All of that is unaccounted for."
    While that probably wasn't the best way to finish. The first line is "all non moving activity is given sleeping level calorie burn - BMR" then he lists all the things that cause your body to burn more while it's awake which are unaccounted for.
  • NancyN795
    NancyN795 Posts: 1,134 Member
    Kidominos wrote: »
    Kidominos wrote: »
    LOL..

    Many people are brand new to owning a Fitbit so when someone writes something (like BMR is not accounted for) they are going to think he meant what he wrote.

    Bottom line is that no device is 100% accurate. Many of us have been using Fitbit's for a long time now. I don't know about the new styles with the HMR but my One has been very accurate.

    ETA: spelling

    But that's not what he wrote. He said it can't tell the difference between BMR and RMR so it just gives you BMR.

    Ok, so where did he write "it can't tell the difference between BMR and RMR so it just gives you RMR"? I just see where he listed multiple statements and then finished up the paragraph with "All of that is unaccounted for."
    While that probably wasn't the best way to finish. The first line is "all non moving activity is given sleeping level calorie burn - BMR" then he lists all the things that cause your body to burn more while it's awake which are unaccounted for.

    I think what heybales said was correct, but I would also agree that someone new to how a FitBit works could have been confused by how he said it. So, I'm glad it has been clarified.
  • heybales
    heybales Posts: 18,842 Member
    Very true, not only Fitbit - but people new to the concept that you burn calories outside of exercise.

    Look how many people we've seen wonder why they have calorie burn when they wake up in the morning, unaware they burn calories sleeping.

    I'll rethink how to throw out that standard phrase.

    Though, I really don't see how it sounds like I said it doesn't include BMR.
  • jasonschaef
    jasonschaef Posts: 8 Member
    edited March 2015
    I've been using a Charge for 2 months now. Compared to other apps like Runtastic, Endomondo, Nike Running, etc., the fitbit seems more conservative in reporting calories burned for the same workout. I like this, because I'd rather err on the side of caution. I've lost 40 pounds as of this morning since Jan 1. Just make sure to log everything on MFP and I'd recommend not eating all of your exercise calories. The fitbit/MFP combo has been a great motivator for me. Like others have said, realize that everything's an estimate, both calories in logged on MFP and calories out measured by fitbit. If you're tending to burn more and eat less, you'll lose weight. Tell your doc to go fly a kite.
  • heybales
    heybales Posts: 18,842 Member
    I've been using a Charge for 2 months now. Compared to other apps like Runtastic, Endomondo, Nike Running, etc., the fitbit seems more conservative in reporting calories burned for the same workout. I like this, because I'd rather err on the side of caution. I've lost 40 pounds as of this morning since Jan 1. Just make sure to log everything on MFP and I'd recommend not eating all of your exercise calories. The fitbit/MFP combo has been a great motivator for me. Like others have said, realize that everything's an estimate, both calories in logged on MFP and calories out measured by fitbit. If you're tending to burn more and eat less, you'll lose weight. Tell your doc to go fly a kite.

    I'll bet the doc read the one sensationalized article about people gaining weight using the Fitbit.

    Never mind they didn't touch once on proper usage of the tool in the first place, or accuracy of logging food in the second place.
  • Kidominos
    Kidominos Posts: 1,249 Member

    [/quote]I'll bet the doc read the one sensationalized article about people gaining weight using the Fitbit.

    Never mind they didn't touch once on proper usage of the tool in the first place, or accuracy of logging food in the second place.[/quote]

    Yup, I agree.

    I weigh my food in grams, use a Polar HRM for non step based activities and I have always ate back all my exercise calories. I lost weight at the desired pace by doing so and eat up to my Fitbit TDEE now maintaining.


  • indianwin2001
    indianwin2001 Posts: 296 Member
    I agree Kidominos
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