Bodymedia Fit vs Fitbit accuracy

huntindawg1962

I took your lead to check out the BMF accuracy over time (I don't have a fitbit to try it against but it may be a fun test to buy one and also try it)

I went back over the past 14 days - downloaded the total calories burned on the BMF (I wear it day and night) - then subtracted the calories consumed from the MFP site. Said I should have lost about 6.6 lbs over that time. Low and behold, from my daily tracking of weight I have lost about 6.

So I went back 28 days, did the same, and was within about 2 lbs on the scale compared to what the overall "calories burned minus calories consumed" method would have indicated. I would say the difference was likely portion sizing or estimating or just missing some things.

At least for the BMF - I am finding that it is working pretty reliably . Now I have a lot to lose and I do eat slightly below my BMR at this point but the BMR will be coming down to what I eat and am not planning to adjust that level down - just will let it naturally slow the loss rate.

Did the OP resume his test?

tabinmaine

bump

juliebeannn

BUMP!

does the OP have any updates? just bought a fitbit and was wondering if i should return and get a BFM since they're on sale right now.

rileysowner

I asked the OP, and his suggestion was get a Fitbit not a BMF. Add to this I have several people I know here who by trusting their BMF were putting weight on. Realize that the BMF has an error rate of between 10-30%, neither it nor the fitbit are 100% accurate. I will likely go with the Fitbit.

tabinmaine

I asked the OP, and his suggestion was get a Fitbit not a BMF. Add to this I have several people I know here who by trusting their BMF were putting weight on. Realize that the BMF has an error rate of between 10-30%, neither it nor the fitbit are 100% accurate. I will likely go with the Fitbit.

hummm... I have read the complete opposite.....

rileysowner

I asked the OP, and his suggestion was get a Fitbit not a BMF. Add to this I have several people I know here who by trusting their BMF were putting weight on. Realize that the BMF has an error rate of between 10-30%, neither it nor the fitbit are 100% accurate. I will likely go with the Fitbit.

hummm... I have read the complete opposite.....

Opposite of what? The error rate on the BMF? That error rate is fairly common knowledge. For some it is quite accurate others not so much.

tabinmaine

I asked the OP, and his suggestion was get a Fitbit not a BMF. Add to this I have several people I know here who by trusting their BMF were putting weight on. Realize that the BMF has an error rate of between 10-30%, neither it nor the fitbit are 100% accurate. I will likely go with the Fitbit.

hummm... I have read the complete opposite.....

Opposite of what? The error rate on the BMF? That error rate is fairly common knowledge. For some it is quite accurate others not so much.

No no, not the error rate, I have read that the Bodymedia is more accurate than the FitBit..... they both have error rates, I have read that the BMF is the most accurate on the market

Blondeweightloss

Bought a fitbit but want to know if you can re set it each day as at the moment it rolls into each day and says I have waked 1000's steps when I have only done 600 (have my clock on 24hrs) ... can't get my head around it and not technically minded HELP please. Really looking forward to your experiment

heybales

There is NOTHING on the market that will tell you your TDEE. Everything is just a estimate. I know the fitbit is less accurate than the body bugg.

What about that new backpack indirect calorimeter with facemask to measure your VO2/VO2C as you go about your daily routine?
Optional calorimeter to put your food in to confirm how many calories are really in it?

Oh wait, the mere presence of 40 lbs extra changes the values, especially during vigorous exercise.
And the act of trying to eat burned up food makes you eat less too.

No wonder their sales for a $2000 unit haven't been brisk, to say the least.

Just can't win for losing. Or lose for winning, or whatever it is is when talking about weight loss.

KarinFit4Life

I bought my BMF and have it now for 2 days only, so I'm still learning and testing and will see after a week. Anyway, I've been doing research online to see what other people say and I found this quite interesting:

http://forum.bodybuilding.com/showthread.php?t=141565561&page=1

heybales

I bought my BMF and have it now for 2 days only, so I'm still learning and testing and will see after a week. Anyway, I've been doing research online to see what other people say and I found this quite interesting:

http://forum.bodybuilding.com/showthread.php?t=141565561&page=1

Nothing more than the realization that if you eat too little, your metabolism slows down.

And notice what they are saying at the same time they are saying it's accurate.

That his metabolism must be causing actually less burn than the BMF is reporting.

Because the BMF site calculates your BMR just like MFP, age/height/weight and now there is your sleep metabolism. Adjust it slightly based on temp levels at night, and movement while sleeping.
But that is now the basis for 1 MET of energy use. Now when you move and exercise, X MET's burned. Multiply by the adjusted BMR figure, there's your energy burn for the day.

Sadly it's all based on that BMR, and if as that thread suggests and is true, if you have slowed your metabolism down, the BMF doesn't know that at all, and all calcs will be off.

So the advice is nothing more than what has been said on MFP many times in many places - you many times need to eat more than you are currently, but less than you were before dieting, to lose weight faster.

It's just the BMF can help you to eat more by helping you visually see you are still burning more than you eat.

But get ready, if you have been eating a whole lot less than it recommends, then you may have weight loss while you reset your metabolism, as that other thread mentions a couple times.

KarinFit4Life

Might have weight loss or weight gain?? Sorry, confused....if I eat more to reset my metabolism wont I have an initial gain and then start dropping the weight?
Thanks for your post heybales! Very informative, its great.

mcarter99

I wore a Fitbit and logged food for six months and lost 35 lbs. The burn rates and deficits and my weight loss amount suggested it was fairly accurate.

I used a BB for a while but I couldn't bear the look of it, and the hassle of the USB synch, or the subscription, so I didn't last long. My burn rates weren't that different, IIRC. I never thought the skin impedence stuff could possibly add much. I'm not a sweat-er and I live in a desert so my temp changes without exercise.

Any device is more to watch your relative changes over time, I think. Are you getting more active overall? That sort of thing. We can tweak things to match our weight loss, if needed. Some people tweak their inputs to the Fitbit because they feel their BMR is over/understated.

I think the OP is right to keep the Fitbit and log the workouts manually. Don't both devices recommend logging certain workouts manually, anyway? I know the Fitbit does. It's not designed to track anything with resistance (like weight training) or anything where you're on a device (like a bike). It assumes you're an unfettered body in motion, on the ground, and assigns calories based on that unless you 'tell' it otherwise.

heybales

Might have weight loss or weight gain?? Sorry, confused....if I eat more to reset my metabolism wont I have an initial gain and then start dropping the weight?
Thanks for your post heybales! Very informative, its great.

Oops, got that backwards. Weight gain during that period, correct.

But frankly, even that gain is usually energy stores going on, topping off glucose, ect.

You can increase by about 200 a day for a week, like extra snack. Then next week another 200 by increasing 2 meal sizes. Then another. ect.

That way you'll always still be generally under your TDEE as it goes up.

heybales

I think the OP is right to keep the Fitbit and log the workouts manually. Don't both devices recommend logging certain workouts manually, anyway? I know the Fitbit does. It's not designed to track anything with resistance (like weight training) or anything where you're on a device (like a bike). It assumes you're an unfettered body in motion, on the ground, and assigns calories based on that unless you 'tell' it otherwise.

Good description of true usefulness.

And the BodyMedia actually prevents you from manually logging workouts if you wore the device during that time period.
You can only put in workouts if you remove the device, and manually correct the "off-body" time.

Another reason why I think the FitBit is nicer, auto-replace FitBit estimate with your entered workout.

KarinFit4Life

Might have weight loss or weight gain?? Sorry, confused....if I eat more to reset my metabolism wont I have an initial gain and then start dropping the weight?
Thanks for your post heybales! Very informative, its great.

Oops, got that backwards. Weight gain during that period, correct.

But frankly, even that gain is usually energy stores going on, topping off glucose, ect.

You can increase by about 200 a day for a week, like extra snack. Then next week another 200 by increasing 2 meal sizes. Then another. ect.

That way you'll always still be generally under your TDEE as it goes up.

Awesome! Thank u!
Ive been doing the Eat more to weigh less way for almost six weeks and the scale is moving down again after a 3 month plateau!
So I know its working.

heybales

Awesome! Thank u!
Ive been doing the Eat more to weigh less way for almost six weeks and the scale is moving down again after a 3 month plateau!
So I know its working.

Oh, you are already there then, great news. The BMF will help confirm some things, and potentially correct the estimates you've used to arrive at goal.

Then use your new purchase and information along with that TDEE Deficit method.
You'll need about a week for the BMF to adjust to you, and then after that need 3 24 hr days where you don't workout to get your non-exercise TDEE avg.

Here is spreadsheet to make it easier, in this topic.

http://www.myfitnesspal.com/topics/show/620206-spreadsheet-for-bmr-tdee-deficit-calcs-mfp-tweaks-hrm

KarinFit4Life

Awesome! Thank u!
Ive been doing the Eat more to weigh less way for almost six weeks and the scale is moving down again after a 3 month plateau!
So I know its working.

Oh, you are already there then, great news. The BMF will help confirm some things, and potentially correct the estimates you've used to arrive at goal.

Then use your new purchase and information along with that TDEE Deficit method.
You'll need about a week for the BMF to adjust to you, and then after that need 3 24 hr days where you don't workout to get your non-exercise TDEE avg.

Here is spreadsheet to make it easier, in this topic.

http://www.myfitnesspal.com/topics/show/620206-spreadsheet-for-bmr-tdee-deficit-calcs-mfp-tweaks-hrm

You are great, thank you so much for being so kind! Not too many on mfp like that.
Amazing spreadsheet! Thank you so much!

mymelody_78

BUMP

JanePublic

I've been wearing both and found them to be very close in terms of data reporting.. Often the fitbit reports more steps, the bodymedia armband reports a slightly higher calorie burn, but overall it seems quite negligible. I am wearing the Link armband more, I prefer it's data feedback, app, and website reports.

PosterGuy1

I ordered a Fitbit earlier this week.