Calorie Burn Total Changing and Wrong

[Koshka]

I honestly don't know what is causing this.  Each night at midnight I make sure I sync my Fitbit and I record my calorie burn information in a spreadsheet.  I've done this for a couple of years and know that it stays the same the next morning and thereafter.

I got my Blaze a little over a week ago.  I had a Charge HR on my account, but I removed it and set it up on a separate account so I could at times wear both and compare them.

Anyway, since I've had my Blaze I've been recording my burned calories at the end of the night.  I was just looking something and realized that my calorie burn info shown on the Fitbit.com dashboard and on the iOS app for any day from Thursday to at least the beginning of this year (I didn't go back farther) is wildly different from what it was 2 days ago.  For example, it shows that on Wednesday I burned 1630 calories but my spreadsheet is at 1513.  Last Saturday is shown as 1844 calories burned online and on the app, but my spreadsheet says 1501.  I know from past experience that the lower numbers that I recorded on my spreadsheet are way more correct than the higher numbers.

So -- is this a Blaze issue or something else?  If something else, any idea what?  Again, the bizarre thing is that my calorie burn information has been retroactively changed going back for at least months.

[Rich_Laue]

I'd the Blaze was truly synced before midnight, then the data us on the Fitbit server, and it should be a server, app, or dashboard issue.  

My thoughts would be is to whew both units amd sync them both,  record the calories and check the next day.  Personally i wpuld alao check the steps amd milage.  Ill do tjis wroth my account tonight. 

[MikeF]

Have you entered a new weight figure recently? When you change your weight, the Fitbit server recalculated past data based on the new weight. It isn't only carried forward to the future.

[Koshka]

No, I haven't entered a new weight lately and it isn't that.  I have been careful to look at this.  Until just 2 days ago, if I checked in the morning it matched what my calorie burn was when I synced at midnight (the point where my tracker went from one day to the next).

If the changes were just a few calories difference it wouldn't be a big deal.  But, these are huge differences for me, often 200 to 300 calories difference.

Now to give a factor that I don't think matters but maybe so. I have had my RMR tested so know my RMR is less than that used by the Fitbit formula.  Basically the Fitbit formula overstates my calorie burn since it gives me an RMR that is about 100 calories too high.

So, months again I went in and changed my height in Fitbit to get an RMR that is accurate.  Now, when this high calorie burn showed up my first thought was that maybe my height got changed back to my actual height.  But I checked and it hasn't been.  So that doesn't seem to explain it.

[bellember]

Is this bug somthing that Fitbit is going to fix? I don't see why past numbers would change when the weight was logged differently at that time - the number should be accurate to your weight during that timeframe.

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@MikeF wrote:

Have you entered a new weight figure recently? When you change your weight, the Fitbit server recalculated past data based on the new weight. It isn't only carried forward to the future.

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[Rich_Laue]

Is is a big @bellember maybe, maybe not.. It is a result of fit it's decision to save necessary info and calculate the rest when the page is requested. 

There are some settings like Stride should not change and this idea works fine with. Stats like your weight should really have the weight for the day stored.. Fitbit doesn't do this and calculates the calories displayed based on the users current weight. 

This is why you can see calories on days before a Fitbit was attached to the account. 

[bbarrera]

Fitbit has my weight history, so it's a poor decision to ignore that info. That's why we have servers and databases in the cloud, to properly account for things in the past. I'd call it a bug. Annoying, but a bug given they have the info.

My stride is very different when pacing at the office, or casually walking 17 minute miles, or power walking 13-14 minute miles. Stride does in fact change. That's the attraction of having GPS measure distance while walking, hiking, biking, running, etc.