Fitbit vs. TDEE and MFP

heyjude345

OK...so here's my question. I use a Fitbit and have it synced to MFP. My TDEE is 1824 and I have MFP set to 1770 calories per day. My Fitbit is set for a deficit of 500 calories a day.

Yesterday Fitbit showed a calories expended at 2,054 and my calorie intake was 1612 so I was over by 58 calories a day from my desired 500 calorie a day deficit.

MFP showed 1770 - 1612 calories eaten + 57 calories credited from Fitbit adjustment so I had 215 calories remaining.

Which should I follow? Or am I doing something wrong along the way in my calculations?

heybales

The deficit set on Fitbit is irrelevant to the math.
It merely sends daily step and calorie total to MFP, when calories go up 100 higher than prior sync.

MFP is estimating your non-exercise TDEE, purely daily activity, based on your selection (guess) of activity level.

Fitbit is seeing everything, and sending that total over.

So MFP is correcting itself for who knows what - could be exercise, could be increased daily activity movement - doesn't matter.

If they are both set to the same deficit amount, and the syncs are working - the end of the day results will be about the same.
If you custom set an eating goal - then that doesn't apply.

But following 2 roads to the same destination is usually aggravating and not useful (especially if a man is driving not asking for directions!).

Which is why majority use Fitbit for all things movement related - manually add workouts there that Fitbit is bad at estimating calorie burn on.

Use MFP for eating related - goals and meal logging.

Might read through this FAQ, first section especially couple times.

http://community.myfitnesspal.com/en/discussion/10098937/faq-syncing-logging-food-exercise-calorie-adjustments-activity-levels-accuracy/p1