Fitbit overestimating daily calories?
ekat120
Posts: 407 Member
I got a Fitbit the other day and have worn it for 3 full days now. The first day I took about 21,000 steps (including a 4 mile run) and it said I burned about 2,500 Cals. The second day I took 11,400 steps (no run that day) and it said I burned 2,200 Cals. Yesterday I took 32,000 steps (including 2 runs of just over 3 miles each--I did a lot of walking yesterday!) and it said I burned over 3,000 Cals.
When I calculate my BMR using the same formula Fitbit uses (Mifflin-St. Jeor I think) and adjust it for lightly active, it puts me at closer to 1,900 Cals per day. At 80 Cals/mi running, that would put me at about 2,200, 1,900, and 2,400 Cals. Am I really that much more active than that? Has anyone else encountered this issue? I triple-checked all my stats on their website, and I've entered everything accurately.
When I calculate my BMR using the same formula Fitbit uses (Mifflin-St. Jeor I think) and adjust it for lightly active, it puts me at closer to 1,900 Cals per day. At 80 Cals/mi running, that would put me at about 2,200, 1,900, and 2,400 Cals. Am I really that much more active than that? Has anyone else encountered this issue? I triple-checked all my stats on their website, and I've entered everything accurately.
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Replies
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I'm glad you asked this because I am having the same issue. It seems like it is overestimating calories for me too. Hopefully someone has an answer for us. Saving my spot.0
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I don't count the calories my Fitbit tries to give me as exercise calories. I am currently about 170lbs overweight, having lost 46 and I mostly just use it to get an idea how much I am moving. I took 9200 steps yesterday and it tried to give me 500+ extra calories to eat! So, yes, I think it overestimates calories, so far as I can tell.0
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The Fitbit calculates the total calories you'd burn in a day, including those just for existing. If you calculate your TDEE, the numbers should be similar.0
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You aren't lightly active. I would use very active or even extra active on the day you had two runs!0
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Ummmm....do you really think going for 2x 3 mile runs and what not is lightly active? Keep in mind that you also just burn calories being alive...a whole bunch of them and Fitbit is going to include those in that number, it's not just the calorie you are burning from you deliberate exercise and steps taken...you burn a **** ton of calories just existing. On top of that you just have stuff like driving the car, doing the dishes, cleaning, etc...this stuff all adds to your "burn".
One major issue here (as evidenced by some of the posts on this very thread) is that people vastly underestimate the caloric needs...very often people need far more fuel than they think they do. When I first started tracking this kind of stuff I thought, "no way I need 3,000 calories to maintain my weight...that has to be too much." Guess what....a bit over a year into maintenance and I need right around 3,000 calories to maintain my weight with my activity level.0 -
The Fitbit calculates the total calories you'd burn in a day, including those just for existing. If you calculate your TDEE, the numbers should be similar.
I know that part (unlike apparently everyone on the Fitbit forums, which is why I posted here instead
) But I'm pretty sure my TDEE is closer to the low 2,000s (1,900 for lightly active, plus about 300-400/day average for running).You aren't lightly active. I would use very active or even extra active on the day you had two runs!
I'm wondering about this. I add my runs separately because they vary from day to day and figure I'm lightly active when you don't count those, but I've definitely been walking more since I got the Fitbit (yay!). My (unfortunately extensive) experience counting calories and losing weight puts me at 1,900-2,000 to maintain without exercise, but maybe I've just been that much more active than usual the past few days? I'll gladly eat 3,000 Cals if I can!
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I got a Fitbit the other day and have worn it for 3 full days now. The first day I took about 21,000 steps (including a 4 mile run) and it said I burned about 2,500 Cals. The second day I took 11,400 steps (no run that day) and it said I burned 2,200 Cals. Yesterday I took 32,000 steps (including 2 runs of just over 3 miles each--I did a lot of walking yesterday!) and it said I burned over 3,000 Cals.
When I calculate my BMR using the same formula Fitbit uses (Mifflin-St. Jeor I think) and adjust it for lightly active, it puts me at closer to 1,900 Cals per day. At 80 Cals/mi running, that would put me at about 2,200, 1,900, and 2,400 Cals. Am I really that much more active than that? Has anyone else encountered this issue? I triple-checked all my stats on their website, and I've entered everything accurately.
The Fitbit calorie total is your TDEE for that day. What did that come to when you calculated it?0 -
The scoobyworkshop.com calculator gives 2,110 for 3-5 hrs/wk of moderate activity (I run, mostly at an easy pace, 4-5 hrs/wk). 5-6 hrs/wk of strenuous activity gives 2,348. Maybe I'm just more active than I think? :huh:0
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32,000 steps is a lot, 3 hours running or 4.5 hours walking approx for me. My fitbit would be up around 3,000 calories at that, though I only got there once - 10,000 is a high enough target for me.0
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Before I got my FitBit, about a year ago, I had calculated my TDEE using various calculators, MFP, etc. I always came up with numbers like 1,700-1,800 because I was thinking, "Sedentary, office job, with a daily walk or some additional exercise 2-3 times/week". Once I got my Fitbit, and started seeing how many steps I take and calories I burn, just from the normal day to day stuff, I realized I had been underestimating. I don't run, but I do average 14K steps/day and I do some circuit training a couple times a week. My average calories burned according to FitBit are about 2,100 - so essentially that is my TDEE. When I changed my activity settings on MFP to lightly active, and then active, it got my numbers much closer to what FitBit was saying - and my weight loss continued at a 0.5lb/week rate (when I took 250 cal deficit from my numbers) and then easily transitioned into maintenance. I've found FitBit to be very accurate, and I get to eat more food!
TL/DR - trust the FitBit, eat more food.0 -
I've seen this guideline tossed around (and, comparing my Fitbit TDEEs to the various charts, it seems dead on for me)
Sedentary = <5000 step
Low Active = 5000-7499 steps
Somewhat Active = 7500-9999 step
Active = 10000-12499 steps
Highly Active = 12500+ steps
And you think 32,000 steps is lightly active? :huh: Even if you back out 6 miles of running, that's maybe only 12,000 or so (give or take) of your steps, leaving you 20,000 of general activity....0 -
I got a Fitbit the other day and have worn it for 3 full days now. The first day I took about 21,000 steps (including a 4 mile run) and it said I burned about 2,500 Cals. The second day I took 11,400 steps (no run that day) and it said I burned 2,200 Cals. Yesterday I took 32,000 steps (including 2 runs of just over 3 miles each--I did a lot of walking yesterday!) and it said I burned over 3,000 Cals.
When I calculate my BMR using the same formula Fitbit uses (Mifflin-St. Jeor I think) and adjust it for lightly active, it puts me at closer to 1,900 Cals per day. At 80 Cals/mi running, that would put me at about 2,200, 1,900, and 2,400 Cals. Am I really that much more active than that? Has anyone else encountered this issue? I triple-checked all my stats on their website, and I've entered everything accurately.
No, that is not the formula that fitbit uses. I don't know where you got that idea.
Fitbit uses a proprietary calculation based or correspondence curves they have researched.
You can read a little about that here : http://blog.fitbit.com/a-brief-look-into-how-the-fitbit-algorithms-work/
(And at 3000) steps you aren't lightly active. My own calculation show the fitbit to be pretty close to what I achieve using other evaluation means. (Without going into metabolic testing methods)0 -
32,000 steps would put me at about 18 miles.0
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No, that is not the formula that fitbit uses. I don't know where you got that idea.
Fitbit uses a proprietary calculation based or correspondence curves they have researched.
You can read a little about that here : http://blog.fitbit.com/a-brief-look-into-how-the-fitbit-algorithms-work/
(And at 3000) steps you aren't lightly active. My own calculation show the fitbit to be pretty close to what I achieve using other evaluation means. (Without going into metabolic testing methods)
Thanks. That link was helpful. Yesterday was a bit of an anomaly, but I guess the consensus is that I'm more active than I thought. Or maybe just more active now that I have the Fitbit (which is the whole reason I got it, I guess!). I guess that means I get to eat more! Yay!0 -
32,000 steps would put me at about 18 miles.
It was a little over 15 for me (5‘6.5”). I went to a street festival and had to walk back and forth to the car parked almost a mile away to drop off/retrieve stuff before and after the 5k. Plus I walked around the festival and to the store earlier in the day.0 -
The Fitbit calculates the total calories you'd burn in a day, including those just for existing. If you calculate your TDEE, the numbers should be similar.
^^^ this!!!
i don't think mine overestimates. i went for a 30 min walk and gave me an extra 300+ cals. i used another app to track the same walk and gave me almost exactly the same!
i personally have mine linked to MFP and love seeing the cals in/ cals out....i think it works great!0 -
Ummmm....do you really think going for 2x 3 mile runs and what not is lightly active? Keep in mind that you also just burn calories being alive...a whole bunch of them and Fitbit is going to include those in that number, it's not just the calorie you are burning from you deliberate exercise and steps taken...you burn a **** ton of calories just existing. On top of that you just have stuff like driving the car, doing the dishes, cleaning, etc...this stuff all adds to your "burn".
One major issue here (as evidenced by some of the posts on this very thread) is that people vastly underestimate the caloric needs...very often people need far more fuel than they think they do. When I first started tracking this kind of stuff I thought, "no way I need 3,000 calories to maintain my weight...that has to be too much." Guess what....a bit over a year into maintenance and I need right around 3,000 calories to maintain my weight with my activity level.
^^ this allso! great explanation0 -
That's fair. My general point is that you have obviously burned a crapton of calories on the days you've worn the fitbit. I'm not saying it's definitely accurate, but the numbers don't seem crazy, either.32,000 steps would put me at about 18 miles.
It was a little over 15 for me (5‘6.5”). I went to a street festival and had to walk back and forth to the car parked almost a mile away to drop off/retrieve stuff before and after the 5k. Plus I walked around the festival and to the store earlier in the day.0 -
Some time after 2009, Fitbit switched to the Mifflin-St Jeor formula for their BMR estimate, I believe.
I agree with the person above who said your steps don't match your run length. It seems like you were very active even in addition to 7 miles of running in one day.
A Fitbit was pretty accurate for me through 35 lbs. of weight loss in 2010. Now, if anything, mine seems to underestimate, but I'm older and smaller and less active, too.
Also, do you have a Flex? Those are less accurate and some will think you're walking when you're typing and that sort of thing. Might be worth a quick typing test to see, or whatever you do for a living.0 -
Some time after 2009, Fitbit switched to the Mifflin-St Jeor formula for their BMR estimate, I believe.
I agree with the person above who said your steps don't match your run length. It seems like you were very active even in addition to 7 miles of running in one day.
A Fitbit was pretty accurate for me through 35 lbs. of weight loss in 2010. Now, if anything, mine seems to underestimate, but I'm older and smaller and less active, too.
Also, do you have a Flex? Those are less accurate and some will think you're walking when you're typing and that sort of thing. Might be worth a quick typing test to see, or whatever you do for a living.
Good point. I do have the Flex. I just tried typing (lots of that in my job), and it didn't appear to be counting. I've watched it in the car, which is another place I've heard people have issues, and it doesn't give me any steps then. Looking at the log, it seems on par with my activity, so I think it's counting the steps correctly. It just seemed like it was overestimating my TDEE based on those steps. But based on your and others' experience, It sounds like it's probably about right.
I'm going to follow it for a while and see how my intake and activity match up with any weight changes.0 -
TL/DR - trust the FitBit, eat more food.
^^^^^ THIS
When I switched from trying to figure out net calories vs TDEE - 20% vs less 500 a day to "eat what the Fitbit tells me to for this day," I started losing regularly.0 -
For me, and we may have dissimilar BMR, I would 'sanity check' it like this: 32000 steps minus say 2000 for sedentary = 30,000. Divide by around 2000 steps/mile = around 15 miles of 'activity'. Times 100 calories/mile = 1500 calories above BMR * sedentary rate. For me that would be around 3000, I think. So it sounds feasible. But my BMR is only in the 1300s, so 1500 for a sedentary day isn't crazy. 0
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Dude...DUDE! You do about as many steps in 1 day as i do in 3-4! And you think you're lightly active? That right there shows a real lack of understanding about how all this works. "lightly" active is, at the very least, under 5,000 steps. You're what...6 times that? Uhhhhh yeahhhhhhh
So you're a mega-stepper. And mega steppers burn tons of calories so if fitbit is telling you you're burning a few thousand calories, believe it. I've spent the past year experimenting with my fitbits questioning "is it giving me the right numbers? Does this make sense?" out of my OCD paranoia and need to have everything be just right. I've had the ONE and now the flex and my conclusion: Fitbit is ridiculously accurate for step related activities, so save yourself the trouble and just trust it.
And now i have a goal. To beat you in steps! I think the most i've ever gotten in a single day was something like 17,000. Now i feel like a wimp0 -
The Fitbit calculates the total calories you'd burn in a day, including those just for existing. If you calculate your TDEE, the numbers should be similar.
I know that part (unlike apparently everyone on the Fitbit forums, which is why I posted here instead ) But I'm pretty sure my TDEE is closer to the low 2,000s (1,900 for lightly active, plus about 300-400/day average for running).You aren't lightly active. I would use very active or even extra active on the day you had two runs!
I'm wondering about this. I add my runs separately because they vary from day to day and figure I'm lightly active when you don't count those, but I've definitely been walking more since I got the Fitbit (yay!). My (unfortunately extensive) experience counting calories and losing weight puts me at 1,900-2,000 to maintain without exercise, but maybe I've just been that much more active than usual the past few days? I'll gladly eat 3,000 Cals if I can!
OP, I haven't read through all of the rest of the comments yet, and maybe I have misread something, but this is what I have understood so far:
-Your BMR has been calculated by you using a website to be around 1900 calories a day.
-You have calculated your TDEE on a website to be in the low 2,000s (TDEE being BMR plus all of the movement you do aside from just existing).
-Your Fitbit is telling you that you have burned 2200-3000 cals, depending on your exercise for that particular day (running vs. not running as much, etc.).
From those 3 points, the Fitbit seems to be calculating your caloric burn for the day pretty accurately. I think perhaps you have underestimated your activity or workout level on the TDEE calculator. I would say you are definitely more than lightly active.
Try recalculating your TDEE on iifym.com (I find this to be more accurate based on my numbers), and select a higher activity level.0 -
You have to understand ... that "These things are just estimations".
Same with those online calculators. They are math calculations bases on the typical person of your stats. They will not always be accurate.
The Fitbit ... which sits on my desk due to the dreaded Fitbit rash, is just that .. a toy that tried to figure out your burns based on your stats.
BMR * 1.2 = sedentary TDEE. This increases up to 1.9x for very active.
But they are still just estimates ... unless you are in a lab you are just guessing.
So .. do what I do, ignore it but my Fitbit I think is pretty close for me.0 -
The Fitbit calculates the total calories you'd burn in a day, including those just for existing. If you calculate your TDEE, the numbers should be similar.
I've found this to be true. It is fairly accurate for me.0 -
The Fitbit ... which sits on my desk due to the dreaded Fitbit rash, is just that .. a toy that tried to figure out your burns based on your stats.
Then why didn't you return it and get the flex or something? Fitbit offered refunds to everyone that wanted to return their force0 -
Lightly active... seriously? Lightly active is 8000 steps a day, probably less...0
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I think she figured 1900ish was 'lightly active' so with her running maybe 2400 (not 3000).0
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For me, and we may have dissimilar BMR, I would 'sanity check' it like this: 32000 steps minus say 2000 for sedentary = 30,000. Divide by around 2000 steps/mile = around 15 miles of 'activity'. Times 100 calories/mile = 1500 calories above BMR * sedentary rate. For me that would be around 3000, I think. So it sounds feasible. But my BMR is only in the 1300s, so 1500 for a sedentary day isn't crazy.
That makes sense.So you're a mega-stepper. And mega steppers burn tons of calories so if fitbit is telling you you're burning a few thousand calories, believe it. I've spent the past year experimenting with my fitbits questioning "is it giving me the right numbers? Does this make sense?" out of my OCD paranoia and need to have everything be just right. I've had the ONE and now the flex and my conclusion: Fitbit is ridiculously accurate for step related activities, so save yourself the trouble and just trust it.
This is me--OCD and wanting everything calculated out just right! And a mega data junkie.OP, I haven't read through all of the rest of the comments yet, and maybe I have misread something, but this is what I have understood so far:
-Your BMR has been calculated by you using a website to be around 1900 calories a day.
-You have calculated your TDEE on a website to be in the low 2,000s (TDEE being BMR plus all of the movement you do aside from just existing).
-Your Fitbit is telling you that you have burned 2200-3000 cals, depending on your exercise for that particular day (running vs. not running as much, etc.).
From those 3 points, the Fitbit seems to be calculating your caloric burn for the day pretty accurately. I think perhaps you have underestimated your activity or workout level on the TDEE calculator. I would say you are definitely more than lightly active.
Try recalculating your TDEE on iifym.com (I find this to be more accurate based on my numbers), and select a higher activity level.
I meant my BMR+NEAT(+maybe something else I'm forgetting that plays into TDEE?) was about 1900. Then a few hundred for exercise for a TDEE in the low 2,000s. The Fitbit is giving me closer to 2,500 for a "typical" day (2,200 without formal exercise). I think it's pretty accurate for BMR, but it's the NEAT (non-exercise activity thermogenesis) that seemed high.
I'm glad to hear that it's been accurate for others. I don't consider myself to have a low metabolism, so if it's accurate for others I'd imagine it is for me, too. I guess I'm just more active than I thought (and have been making a somewhat concerted effort to walk more consistently since I've been wearing it, though I've always walked quite a bit). I guess if I'm delusional at least it's in the "right" direction :laugh:0
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