Is this the logical next step? (trouble with fitbit and accurate logging)

stephnz1989

I haven't lost weight in two months. My fitbit seems to greatly be overestimating how many calories I've burnt. My weightloss was set to 0.25kg a week (different account), and I was eating back all of my exercise calories from my fitbit. I am wondering if this is why I wasn't losing, or if I was using too many user submitted food entries in the database and not double checking them.

Have now set my weightloss to 1kg a week, with the intention of eating all of my exercise calories back. Will this result in a loss, or will the fitbit overcorrect itself? (I hope that makes sense).

cwolfman13

@ .25kg per week (.5 Lbs) you pretty much have to be spot on with everything which is difficult to do when you're working with something that isn't an exact science. There is literally zero room for error and given that much of this is estimation, that small of a calorie deficit is nearly impossible to zero in on. Going from .25kg to 1kg is a big jump in the size of your deficit, but there's considerably more room for error.

stephnz1989

cwolfman13 wrote: »

@ .25kg per week (.5 Lbs) you pretty much have to be spot on with everything which is difficult to do when you're working with something that isn't an exact science. There is literally zero room for error and given that much of this is estimation, that small of a calorie deficit is nearly impossible to zero in on. Going from .25kg to 1kg is a big jump in the size of your deficit, but there's considerably more room for error.

Thanks, that's helpful.

spacetreemonkey

I want to know this too.

Lietchi

If you were set at a rate of 0.25 kg per week and you actually had a stable weight (no weight gain either), it means that the error (whether it's your logging and/ or your Fitbit) is only around 275 calories per day. If I were you, I would set my weight loss rate at 0.5kg per week, which should give a weight loss rate of 0.25 kg per week. Going to a full 1kg per week seems a bit excessive.

That being said, a rate of 0.25kg per week does require a bit of patience because a shower rate of loss can be masked by regular weight fluctuations for a longer time. I recommend using a weight trending app like Libra or Happyscale to better discern your weight trend (it's still no guarantee, you might still see an occasional uptick in the trend at a slow rate of loss).

spacetreemonkey

Lietchi wrote: »

If you were set at a rate of 0.25 kg per week and you actually had a stable weight (no weight gain either), it means that the error (whether it's your logging and/ or your Fitbit) is only around 275 calories per day. If I were you, I would set my weight loss rate at 0.5kg per week, which should give a weight loss rate of 0.25 kg per week. Going to a full 1kg per week seems a bit excessive.

That being said, a rate of 0.25kg per week does require a bit of patience because a shower rate of loss can be masked by regular weight fluctuations for a longer time. I recommend using a weight trending app like Libra or Happyscale to better discern your weight trend (it's still no guarantee, you might still see an occasional uptick in the trend at a slow rate of loss).

I think she is asking if the fitbit is giving too many exercise calories and cancelling out the 0.25kg weight loss from the mfp app?

Lietchi

spacetreemonkey wrote: »

Lietchi wrote: »

If you were set at a rate of 0.25 kg per week and you actually had a stable weight (no weight gain either), it means that the error (whether it's your logging and/ or your Fitbit) is only around 275 calories per day. If I were you, I would set my weight loss rate at 0.5kg per week, which should give a weight loss rate of 0.25 kg per week. Going to a full 1kg per week seems a bit excessive.

That being said, a rate of 0.25kg per week does require a bit of patience because a shower rate of loss can be masked by regular weight fluctuations for a longer time. I recommend using a weight trending app like Libra or Happyscale to better discern your weight trend (it's still no guarantee, you might still see an occasional uptick in the trend at a slow rate of loss).

I think she is asking if the fitbit is giving too many exercise calories and cancelling out the 0.25kg weight loss from the mfp app?

We have no way of knowing whether the error is with the Fitbit or with her logging (or both) unless OP gives more info. But as I said, the error isn't that big, only 275 calories per day if she is maintaining her weight instead of losing 0.25kg per week.

spacetreemonkey

Lietchi wrote: »

spacetreemonkey wrote: »

Lietchi wrote: »

If you were set at a rate of 0.25 kg per week and you actually had a stable weight (no weight gain either), it means that the error (whether it's your logging and/ or your Fitbit) is only around 275 calories per day. If I were you, I would set my weight loss rate at 0.5kg per week, which should give a weight loss rate of 0.25 kg per week. Going to a full 1kg per week seems a bit excessive.

That being said, a rate of 0.25kg per week does require a bit of patience because a shower rate of loss can be masked by regular weight fluctuations for a longer time. I recommend using a weight trending app like Libra or Happyscale to better discern your weight trend (it's still no guarantee, you might still see an occasional uptick in the trend at a slow rate of loss).

I think she is asking if the fitbit is giving too many exercise calories and cancelling out the 0.25kg weight loss from the mfp app?

We have no way of knowing whether the error is with the Fitbit or with her logging (or both) unless OP gives more info. But as I said, the error isn't that big, only 275 calories per day if she is maintaining her weight instead of losing 0.25kg per week.

Oh well that's good to know.

mark221104

Fitbit tests are shown to be up to 20% off when calculating calories used. There are so many variables that using this alone to set your maintenance calories could lead to little or no results. There are Well established mathematical formulas for determining your caloric requirement. Use these instead as your baseline. Remember your body will adapt over time to any increase or decrease in your food intake

kshama2001

stephnz1989 wrote: »

I haven't lost weight in two months. My fitbit seems to greatly be overestimating how many calories I've burnt. My weightloss was set to 0.25kg a week (different account), and I was eating back all of my exercise calories from my fitbit. I am wondering if this is why I wasn't losing, or if I was using too many user submitted food entries in the database and not double checking them.

Have now set my weightloss to 1kg a week, with the intention of eating all of my exercise calories back. Will this result in a loss, or will the fitbit overcorrect itself? (I hope that makes sense).

If your fitbit is synced to MFP, the calories FB sends over should be correct. If you are just looking on your FB, the calories include your BMR, so yes, that's higher than you should eat back.

https://help.fitbit.com/articles/en_US/Help_article/1141.htm#:~:text=Fitbit devices combine your basal,to estimate your calories burned.

Fitbit devices combine your basal metabolic rate (BMR)—the rate at which you burn calories at rest to maintain vital body functions (including breathing, blood circulation, and heartbeat)—and your activity data to estimate your calories burned. If your device tracks heart rate, your heart-rate data is also included, especially to estimate calories burned during exercise. The number you see on your Fitbit device is your total calories burned for the day.

AnnPT77

mark221104 wrote: »

Fitbit tests are shown to be up to 20% off when calculating calories used. There are so many variables that using this alone to set your maintenance calories could lead to little or no results. There are Well established mathematical formulas for determining your caloric requirement. Use these instead as your baseline. Remember your body will adapt over time to any increase or decrease in your food intake

And those "well-established formulas" can also be off, since not everyone is average.

Fitness trackers and MFP's exercise database also use "well established formulas" to estimate exercise, BTW.

So, for the OP:

Yes, the Fitbit estimate could be off.
Yes, the calorie logging could be imprecise or incomplete.
. . . and also, yes, the base calorie estimate for the OP could also be off for nonobvious reasons, because that can happen.

It's rare for the "well established formulas" for base calories to be extremely far off for people, because this is a distribution with a relatively small standard deviation, i.e. a relatively tall, narrow bell curve. There are still people farther out from the mean value that the calculators spit out, and a very few surprisingly fat out, because that's how statistical distributions work.

https://examine.com/articles/does-metabolism-vary-between-two-people/

As far as I can tell, the "well established formula" estimate is something like 25-30% off for me . . . that much too low, and I'm pretty sure I haven't been logging 25-30% more food than I actually ate for 8+ years now, while losing then maintaining my weight.

Assuming that logging is reasonably accurate (which it's too soon to conclude in this case), one's own weight change results can provide more accurate estimates of calorie needs than the "well established formulas". I agree that the formulas are the best starting point.