FitBit Seems Off

samammay

So ive been using MFP for 3 weeks now and have had great results. I set the daily calories to 1900 (1.5 pound/wk, sedentary + 100 cals because i'm not actually sedentary). Lost about 10 pounds since I started and feel great.

I got a FitBit One on Saturday and each of the last 3 days its been adjusting my calories by almost 1000. I changed my MFP daily to 1530 (sedentary, 2 lb/wk) but i'm still being told to eat over 2500 cals/day plus exercise (5x/wk)

Is there any way that's right? Have I just been starving myself the last 3 weeks by underestimating my daily activity?

FitBit has counted ~14k steps and 20 flights of stairs since I began.

Thanks!

Minks_esposa

I heard the fitbit overestimates steps and activity. I can't answer your question though since I have a bodymedia armband.

Francl27

Unsynchronize it, seriously. It's just a huge mess. And I'm not sure it works well with MFP and the 'lose 2 lb a week' setting.

Personally, I don't have them synchronized, I just see what my average is with my fitbit after I add some exercise calories (I don't move with bodypump, for example, so it doesn't really register on my fitbit), and eat that minus 20% every day. Just much easier than having to worry about fitbit adding weird random calories every day.

lcfairbairn74

Have you set your Fitbit to the '2 pounds a week loss' setting as well?

Mr_Knight

It's important to remember that FitBit doesn't measure calorie burn - it makes some guesses based on a very small amount of sensor data, and then calculates a number based on models not unlike those used by MFP or Strava or whatever.

Like MFP, it will need to be calibrated (and recalibrated) for each individual.

shadow2soul

Fitbit actually underestimates for me. I have it synced with MFP and based on the calories in vs out for the month of august. I should have lost a little over 4lbs, but in reality I lost a little over 7lbs.

On really active days I can eat up to 2500 calories and still be at a deficit.

JeffGDDG

I think I may have finally gotten mine close. You have to turn on the negative calorie adjustment here. Then I reset my goals on MFP to active and lose 2 pounds a week. And I set my workout goal to 6 days a week, 30 minutes a day. I am on my feet 8 hours a day walking four days a week at work. All I did at Fitbit was put in my age/sex/height and my stride for running and walking. Any step type exercise I log there. Any non-step exercise I log here. It takes a little getting used to. My daily calories start at 1810 and with a 1000 a day deficit I have to burn 2810. Right now it shows I should eat 2100 calories today but since I have the negative calories adjustment that number will slowly get lower as long as I am somewhat sedentary the rest of the day. I've input my numbers into a lot of sites and my bmr averages around 2000 calories so I shoot to eat the 1810 mfp gives me and on days when I work and burn a lot of calories I'll end up with a few hundred more. Not sure how clear that all was...

glowgirl14

The goals have to match for you to get anything remotely close to reality.

Your burn on FB needs to be set to roughly the same as your TDEE on MFP.
Your activity level
Your amount to lose/week

Also, if you're getting 14k steps a day, you're not remotely sedentary. There are active people on my FL that get less than 10k. You need to set MFP to active...If the two sites think you're sedentary, and trying for a 1900 calorie goal, you're going to get crazy amounts of exercise calories added.

Do you know your TDEE? What do the calculators say, and what does FB say you burn in a day?

I have mine set pretty well I think. I burn pretty close to what FB thinks I will in a given day, and with the extra calories I get (usually around 2-300/day) I am right at the deficit I want to be. It's not perfect, but it is close.

snazzyjazzy21

Fitbit actually underestimates for me. I have it synced with MFP and based on the calories in vs out for the month of august. I should have lost a little over 4lbs, but in reality I lost a little over 7lbs.

On really active days I can eat up to 2500 calories and still be at a deficit.

QFT

_EndGame_

The Fitbit will give you your TDEE calories, so you'll notice that even if you're sleeping, the Fitbit is clocking calories burnt. You can set your Fitbit to give you a reading of the negative calorie count.

I have the Fitbit One, and even though it's a great little motivational gadget, I found it to overestimate both steps and calories burnt. The last thing I want is a false calorie reading, as I tend to eat at least 80% of my exercise calories back.

I would suggest buying a HRM, preferably a Polar FT4 (the one I use) as that, based on your age, weight, height and gender will give you a deadly accurate calorie burn readout, based on your BPM. It can also be used as a pedometer, too!

scrapjen

Have you calculated your TDEE using one of the online calculators? After you've had your Fitbit for a bit, you could see what your average daily burn is and how it compares to an online TDEE estimation.

I LOVE the sync between MFP and Fitbit ... I had Fitbit first, then joined MFP, so I never experienced MFP without a Fibit. I do think those who have MFP first sometimes have trouble adjusting to the Fitbit information coming in.

I have heard others say they think the Fitbit overestimates ... I'm not sure what I think personally, but I guess I figure it's safer to work off that assumtion if weight loss is the goal. I only have MFP and Fitbit set to a one pound loss a week (so 500 decifit), and then I try not to eat back all my exercise calories ... just because the programs SAY I can doesn't mean I feel like I need to. I try to leave 500+ uneaten (I'm not always successful).

I'm uber active, and try to get my daily burn from Fitbit to 3000+, I try to get a 1000+ Fitbit calorie adjustment from my activity (I have myself set to sedentary, so I'll start with a low calorie estimate, it just works better mentally for me). I try to keep my calorie intake around 2000. I just watch the calorie intake #, I don't really pay attention to what I have "left" or my net, just the calories in. It's been working for me.

I really like how my weight updates on both sites, and how the MFP food data goes to Fitbit, for the "Intake vs Burn" graph there. There is no way I could unsyc the two!

samammay

One site has my TDEE at 2859 using the Mifflen method. FB says I have burned 3120 so far today and its only 7pm local time.