calorie burn is "discounted" in myfitnesspal

[Peppermary]

I'm not really sure where to ask this question. I have a new Versa 2 (warranty service) and it correctly uses SmarTrack to detect my runs and fitness walks. When I look at my Fitbit activity log on the web, it shows the calories that I would expect (~300 for a long brisk walk, ~600 for a 5 mile run).  

The only problem is in the data transfer to myfitnesspal. Somehow those calories are being heavily discounted to (for example) 194 for the walk and 400 for the run.

I am hungry and want my calories back 🙂 

Is this a feature or a bug? I remember that my "old" Versa 2 had the opposite problem ... it would give wild amounts of calories to MFP and if I ate those cals, I would have gained a ton of weight. This is definitely a better problem to have, but I just want to understand what it's trying to do.

Thanks for any insight.

[Heybales · Accepted solution]

MFP already expects you to burn a certain number of calories per day with no exercise and your selected activity level.

Say Sedentary it says 2000.

You selected 1 lb weekly loss, 500 cal deficit, eating goal is 1500.

If you do some walking, and are otherwise very sedentary (takes about 4000 steps to move out of sedentary to lightly-active), it could be you are not burning more than already expected for the activity level.

Maybe you selected Lightly-Active on MFP.

So if Fitbit reported to MFP you burned 2250 calories in that day, and you happened to have 900 in exercise in that total, MFP was already expecting you to burn 2000 just being sedentary.

So MFP would give you an adjustment of 2250 - 2000 = 250 calories.

Eating goal correctly 1500 + 250 = 1750.

Still have 500 deficit.

That happens when your exercise is not an overall net increase to your daily burn. Some people get tired from exercise, sit around more when done, less active than normal. Extreme diets also cause people to move less, one of the first responses of body to adapt to foolishness - make you burn less when it can.

Now, that being said - Fitbit does NOT send workouts to MFP, so if you are literally seeing a workout with a smaller calorie burn - it's coming from somewhere else, not Fitbit.

Fitbit sends daily calorie burn (TDEE) and timestamp for MFP to do math with. And steps, but not used in math. If you have accounts linked. Like you see food meal totals on Fitbit, right?

Don't manually enter workouts on MFP. But do on Fitbit if you know of a more accurate calorie burn than what Fitbit saw. Like Weights or intervals will be inflated by Fitbit HR calculations, manual logging is best if you spend a lot of time doing it.

Check to see what else MFP is synced to. If it's getting a workout from another source, it should be sending it back to Fitbit too.

So Fitbit should be showing 2 workouts also, only the last added counts though since Fitbit is a replace-only system.

[Peppermary]

Thank you for that extremely helpful reply! So, to recap, Fitbit has a different method from MFP to calculate what I can eat:

- MFP gives me an estimated base burn (same every day), plus if I manually add a workout in MFP, it adds those calories on a one-for-one basis.

- FitBit tries to calculate what I actually am burning throughout the day, including not just workouts, but also the resulting chill-time when I am less active than my estimated base burn - example, legs tired from running 5 miles.

When the Fitbit device is linked to MFP, Fitbit's method "wins".

You were right,, I did have MFP set to "lightly active." Maybe that's not quite accurate - I'll have to decide what to do there. But to answer your other question, I wasn't seeing specific workouts imported to MFP, but when I saw them on the Fitbit Dashboard, they had pretty much the same calories as when I entered them manually on MFP. Thus, I'm pretty comfortable that the workout calories are accurate. 

I'm actually pretty impressed about how much improved this Fitbit is versus my original Versa 2 which added way too many calories. Or I guess it's the software that improved in the meantime.

Thanks again!

[Heybales]

Correct.

Basically you can view it as MFP gives 4 activity levels to guess between, that is only supposed to be non-exercise time.

Fitbit has probably over 1000 activity levels that includes exercise.

When synced MFP corrects itself to Fitbit's figure.

Regarding which activity level to use - I'd say sedentary, for a reason that may not matter.

MFP takes the Fitbit TDEE and timestamp, and rest of the day is done at MFP activity level rate - so say Lightly-Active, which is BMR x 1.4 per day.

If you eat early dinner, get a Fitbit sync to MFP say 6 pm, and that decides a final snack before you hit the couch and then bed for the night - MFP will be figuring 6 more hours at Lightly-Active rate of burn.

But you are sitting on couch and then sleeping. Fitbit will log that as BMR rate of burn.

The next morning on 1st sync perhaps you see, the prior day will be corrected for that difference.

You may have nailed your eating goal on the nose, but after that 6 hrs is corrected - you have now gone over your goal upon review.

Now - if you go to bed near midnight, eat a final late snack to reach goal close to that - no big whoop no corrections to be applied basically.

Or - if you always finish that last snack and hit the couch & bed the same time each night - you'll learn what that correction is, and just leave that much in the green towards your eating goal. The next morning it'll correct and show you nailed it.

Or - sedentary at BMR x 1.25 helps lessen the effect - though you still may we aware of leaving a tad in the green each night.

The only thing selecting Lightly-Active gives you is a bigger calorie budget at the start of the day to plan on, less adjustments later on.

But if your day is typically the same - you kind of learn how much you have to play with anyway in total, so the end of the day you are still left with minor amounts to eat or skip.

New device may be not going into HR-based calorie burn as much, correctly using step-based for your daily activities. Perhaps in better shape now so not inflated HR? Maybe stride length to get distance is more accurate for resulting calorie burn. Several reasons why improvement.

And several why tweaking may still be needed depending on results and accurate food logging.

[Kris111]

I get very very confused myself with my fitness pal but it somehow mysteriously ends up working when I follow it seems like.

It always says I can basically eat back everything I burnt according to what I have burned on my device. 

[robertwinter]

i just sent you a friend request, maybe we should be friends and jump on some challanges