Fitbit and extra calories

I have been using fitbit for a couple weeks now and have noticed this: during the day mfp tells me that I can eat more based on fitbit but the next day it shows up that the total fitbit calories burned (extra calories) is/was a lot less. Even compared to 11pm at night. I don't understand how it can change so much from 11pm to the next day. This past week I have walked over 10k steps 5 out of seven days. It screws me up because it looks like i can have more for dinner and then it turns out the next day that i was wrong. What is going on?
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Replies

  • Ready2Rock206
    Ready2Rock206 Posts: 9,489 Member
    FitBit assumes you'll maintain your activity level through the entire day. So if you're fairly active FItBt gives you all those calories it predicts you'll earn. Then you sit down to watch tv or go to bed or whatever and stop being as active and FitBit goes oops - time to readjust for the decrease in activity and starts subtracting them.
  • clynnrychly
    clynnrychly Posts: 11 Member
    FitBit assumes you'll maintain your activity level through the entire day. So if you're fairly active FItBt gives you all those calories it predicts you'll earn. Then you sit down to watch tv or go to bed or whatever and stop being as active and FitBit goes oops - time to readjust for the decrease in activity and starts subtracting them.

    You can change the settings so that it doesn't do that though and just gives you an estimated burn up to that point in the day
  • thankyou4thevenom
    thankyou4thevenom Posts: 1,581 Member
    Sounds like you're more active in the morning than the evening. Turn off all day syncing and only sync towards the evening.
    Also since you've been doing this a couple of weeks you should know what your rough daily allowance is. Try to aim for that and then let the Fitbit tell you if you got it right.
  • Elisabuffy19
    Elisabuffy19 Posts: 130 Member
    FitBit assumes you'll maintain your activity level through the entire day. So if you're fairly active FItBt gives you all those calories it predicts you'll earn. Then you sit down to watch tv or go to bed or whatever and stop being as active and FitBit goes oops - time to readjust for the decrease in activity and starts subtracting them.

    You can change the settings so that it doesn't do that though and just gives you an estimated burn up to that point in the day

    How do I change that setting? Thanks!
  • Elisabuffy19
    Elisabuffy19 Posts: 130 Member
    Sounds like you're more active in the morning than the evening. Turn off all day syncing and only sync towards the evening.
    Also since you've been doing this a couple of weeks you should know what your rough daily allowance is. Try to aim for that and then let the Fitbit tell you if you got it right.

    Good advice. Do you know where to adjust syncing? Too bad I can't eat more!
  • dubird
    dubird Posts: 1,849 Member
    Try turning off negative adjustments to MFP. That helped me out a lot! Basically, I have MFP set to an average day's calorie burn for me (derived though lots of trial and error), and if I'm burning more, Fitbit will adjust it for me. Sometimes I'll get to the end of the day, espically on walk days, and realize I need more calories, but overall, I can keep things balanced well.
  • thankyou4thevenom
    thankyou4thevenom Posts: 1,581 Member
    You can do it via the app or the Fitbit website. :)
  • Elisabuffy19
    Elisabuffy19 Posts: 130 Member
    You can do it via the app or the Fitbit website. :)

    Thanks! I just turned it off. On days that I walk over 10k, it only gives me about 50 extra calories. Does that sound right to you? Is it because I am logging exercise in mfp? Or because i have Lightly Active in my profile?
  • thankyou4thevenom
    thankyou4thevenom Posts: 1,581 Member
    You can do it via the app or the Fitbit website. :)

    Thanks! I just turned it off. On days that I walk over 10k, it only gives me about 50 extra calories. Does that sound right to you? Is it because I am logging exercise in mfp? Or because i have Lightly Active in my profile?
    Both. If the activity is step based I'd not bother logging it as that's what the Fitbit is designed for.
    It's usuall recommended to set your activity as sedentary and let the Fitbit take care of the rest. This is just in case you have days where you're not as active. You might be overestimating your burns in those days (although if you've got negative adjustments enabled the Fitbit will still take care of that).
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    At 11pm it should not change by much til midnight. But I can explain why it happens...

    MFP estimates your total burn based on your stats & activity level. For this example, lets go with MFP expects you to burn 2400 per day. MFP expects you to burn 100 per hour. It can't compute enough detail to know when you're sleeping vs when you're active, so every hour is assumed to be 100. (Or 1/24th of your daily total.)

    In reality, perhaps your BMR is 75/hr so when you're sleeping/sitting you're burning 75 or just barely over.

    I've gone thru that to explain this:

    Each time you sync Fitbit to MFP, MFP takes your Fitbit burn total as of X time, and adds 100/hour to project your end of day #. MFP then says you are over or under depending on the result. It changes thru the day, because some hours you're more active than 100/hr and others you're less. But when you're 'done' for the day, and go to bed you are burning the ~75/hour rather than the 100.

    Such as, you wake up at 6am. MFP thinks you should be at 600 burned, but you were sleeping and you're at 75 x 6 or 450 burned. You're 150 behind. From 6-8 am you're showering, getting dressed, misc stuff, driving kids to school. You burn an additional 175, putting you at 625 instead of MFP's prediction of 800. 8-9, you go for a 60 minute walk and burn 300. Now you're at 925, ahead of MFP's 900 prediction by 25. And so on. Then at 9pm, you're done for the day. Fitbit says you're at 2300. MFP expected 2100, so you're up by 200. But from 9-midnight you burn 75/hour instead of 100. So you end the day at 2525. When you check tomorrow, you'll see you were 125 over rather than 200.

    How to 'fix' this? There is only so much you can do. understanding why helps. Set MFP to sedentary and it will be less of a variance. (Maybe then MFP will expect you to burn 90/hour instead of 100.) Or use your Fitbit app, set Fitbit to sedentary (thru teh online dashboard, not app) and then the app will tell you how many you have left as of last sync. To earn more you must move more.
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    Ps-if you're logging exercise in MFP, that is part of the reason why its a bigger gap.

    Continuation from above: MFP expects you to burn 2400. You log 400 exercise calories in an hour, which was 300 extra beyond the 100/hour standard. MFP now expects you to burn 2700. So if you end the day w/ Fitbit saying you burned 2525, you'll have a -175 for Fitbit (you didn't hit 2700) and the logged exercise calories.

    If you log the exercise in Fitbit, it won't change what MFP expects for your total daily. If the exercise is part of the 2525 that you burned for the day, you'll see +125 Fitbit. Same end result, yes, but you'd know not to eat as if you were burning 2700.
  • airbent
    airbent Posts: 150 Member
    You can do it via the app or the Fitbit website. :)

    Thanks! I just turned it off. On days that I walk over 10k, it only gives me about 50 extra calories. Does that sound right to you? Is it because I am logging exercise in mfp? Or because i have Lightly Active in my profile?

    You need to set both MFP and Fitbit to sedentary for fitbit step-based adjustments to be meaningful (where's editorgrrl with that helpful post of hers lol), you also need to have negative calorie adjustments enabled. That's how you get your real TDEE minus deficit from fitbit/MFP. If you have MFP set to lightly active it's going to be estimating your TDEE, but the good thing about having a fitbit is knowing exactly what your TDEE is..
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    Negative calories enabled really only matters if you are less active than MFP expects, and you often see a 0 for Fitbit calories.
  • dubird
    dubird Posts: 1,849 Member
    Negative calories enabled really only matters if you are less active than MFP expects, and you often see a 0 for Fitbit calories.

    No, it actually adjusts your calories at MFP, which is why I don't use it. If I'm over by 100 calories because I wasn't as active as I normally am, oh well. One day here and there isn't going to sabotage me, so I'm cool with that.


    OP, what I did was track my calories burned with the Fitbit for a week WITHOUT exercise. I actually wasn't exercising at the time, but if you are, then use the exercise mode with your Fitbit, and subtract the calories burned in exercise mode from the week's total. Then divide by 7 (or however many days you did this for). That gave me a good estimate of a normal day for me, and I took a deficit off of that. Both MFP and Fitbit are set to sedentary and I'm using that custom calorie total, and that's been working for me.
  • editorgrrl
    editorgrrl Posts: 7,060 Member
    On days that I walk over 10k, it only gives me about 50 extra calories. Does that sound right to you? Is it because I am logging exercise in mfp? Or because i have Lightly Active in my profile?

    Adjustments are the difference between your Fitbit burn (which is TDEE) and your MFP activity level. If (and only if) you enable negative calorie adjustments, you're eating TDEE minus deficit. With them disabled, you never eat at a true deficit on days you burn fewer calories than your MFP activity level.

    Exercise logged in MFP overwrites your Fitbit burn during that time, so it's better to log exercise in Fitbit. If you want your exercise to appear in your newsfeed, post a status update.
    During the day mfp tells me that I can eat more based on fitbit but the next day it shows up that the total fitbit calories burned (extra calories) is/was a lot less. Even compared to 11pm at night.

    Verify that MFP & Fitbit are set to the same time zone:
    http://www.myfitnesspal.com/account/timezone
    https://www.fitbit.com/user/profile/edit
  • cld111
    cld111 Posts: 300 Member
    editorgrrl wrote: »

    Verify that MFP & Fitbit are set to the same time zone:
    http://www.myfitnesspal.com/account/timezone
    https://www.fitbit.com/user/profile/edit

    Oh wow. My time zone in MFP was off. I was having the same issue as the OP. I bet that will help. Thanks!!
  • Elisabuffy19
    Elisabuffy19 Posts: 130 Member
    At 11pm it should not change by much til midnight. But I can explain why it happens...

    MFP estimates your total burn based on your stats & activity level. For this example, lets go with MFP expects you to burn 2400 per day. MFP expects you to burn 100 per hour. It can't compute enough detail to know when you're sleeping vs when you're active, so every hour is assumed to be 100. (Or 1/24th of your daily total.)

    In reality, perhaps your BMR is 75/hr so when you're sleeping/sitting you're burning 75 or just barely over.

    I've gone thru that to explain this:

    Each time you sync Fitbit to MFP, MFP takes your Fitbit burn total as of X time, and adds 100/hour to project your end of day #. MFP then says you are over or under depending on the result. It changes thru the day, because some hours you're more active than 100/hr and others you're less. But when you're 'done' for the day, and go to bed you are burning the ~75/hour rather than the 100.

    Such as, you wake up at 6am. MFP thinks you should be at 600 burned, but you were sleeping and you're at 75 x 6 or 450 burned. You're 150 behind. From 6-8 am you're showering, getting dressed, misc stuff, driving kids to school. You burn an additional 175, putting you at 625 instead of MFP's prediction of 800. 8-9, you go for a 60 minute walk and burn 300. Now you're at 925, ahead of MFP's 900 prediction by 25. And so on. Then at 9pm, you're done for the day. Fitbit says you're at 2300. MFP expected 2100, so you're up by 200. But from 9-midnight you burn 75/hour instead of 100. So you end the day at 2525. When you check tomorrow, you'll see you were 125 over rather than 200.

    How to 'fix' this? There is only so much you can do. understanding why helps. Set MFP to sedentary and it will be less of a variance. (Maybe then MFP will expect you to burn 90/hour instead of 100.) Or use your Fitbit app, set Fitbit to sedentary (thru teh online dashboard, not app) and then the app will tell you how many you have left as of last sync. To earn more you must move more.

    Oh my, thanks so much to you and all the posters! I will read through all of this and adjust. I love numbers so want to get this right!

  • rosebette
    rosebette Posts: 1,659 Member
    cld111 wrote: »
    editorgrrl wrote: »

    Verify that MFP & Fitbit are set to the same time zone:
    http://www.myfitnesspal.com/account/timezone
    https://www.fitbit.com/user/profile/edit

    Oh wow. My time zone in MFP was off. I was having the same issue as the OP. I bet that will help. Thanks!!
    That just happened to me! I was in Arizona for the week, then flew back to New England on Saturday. It somehow merged Saturday's activity into Sunday's so that I had this huge number of calories. Of course, I knew it was inaccurate, but kind of interesting to log way under and be told I'd weigh 104 lbs. if I ate like that every day! Now it's back to normal. By the way, it took several times syncing to get it to the right time. Sync'ing to my cell phone didn't work; only my laptop did.
  • Elisabuffy19
    Elisabuffy19 Posts: 130 Member
    Something is off with my fitbit again. I walked more steps today than yesterday (it's 10:45pm) and it's subtracting 117 activity calories whereas yesterday when I walked less it gave me 28 extra calories to use. Why could this be happening??
  • editorgrrl
    editorgrrl Posts: 7,060 Member
    Something is off with my fitbit again. I walked more steps today than yesterday (it's 10:45pm) and it's subtracting 117 activity calories whereas yesterday when I walked less it gave me 28 extra calories to use. Why could this be happening??

    Your default MFP calorie goal is activity level minus deficit. Your Fitbit burn is TDEE, which is affected by much more than just your step count. Adjustments are the difference between your Fitbit burn and your MFP activity level.

    You may have gotten more steps today, but you burned fewer calories.

    You can learn more in the Fitbit Users group: http://community.myfitnesspal.com/en/group/1290-fitbit-users