FitBit Calorie Burn Over-exaggerated
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afhowell757
Posts: 8 Member
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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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.0 -
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 Loss0 -
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!0 -
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.0 -
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.0
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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.0 -
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.)
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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.0 -
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.0 -
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.0
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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 ok0 -
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
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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).
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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.0 -
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.
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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
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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.0
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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!0
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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.0 -
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.0
