Fitbit Aria scale - Body Fat %

liquoricecat · January 2015

Hi all,

Apologies if this question has been answered a million times over but, if anybody is using the Fitbit Aria, do you happen to know how accurate it is in calculating body fat?

I'm 5ft 8 and am fluctuating between 130 and 134 lbs at the moment. My measurements (when taken manually) are about 36-29-37 (I have naturally big hips and very little definition between hips and waist). When I calculated body fat myself, I came out at about 23-25%. The Aria is saying 29-30%

I do understand the concept of 'skinny fat' and whilst my workouts probably aren't as strenuous as a lot of people on here, I do exercise at least six days a week, and some of that is resistance/strength.

Has anyone else experienced a massively inflated body fat number when using Aria to what they thought?

Phrick · January 2015

Scales that rely on bio-impedance to tell you your body fat are markedly unreliable. Ignore it.

liquoricecat · January 2015

Thanks Phrick. I suspected this but also don't want to kid myself. I will weigh again tomorrow morning when hopefully I won't be so water retentiony.

Phrick · January 2015

Hydration level/water retention is the biggest cause of inaccuracy with bio impedance body fat measurements so if you're "water retentiony" that's your most likely reason for seeing such a higher % than expected.

JoKnowsJo · January 2015

I have the scale too, the nice thing is it relays the weight info

or

to your weekly stats that the fitbit sends to your email, that's the one reason I got it. The percentage thing just annoys me, so I ignore it.

WalkingAlong · January 2015

With a BMI of 20, you're not 'skinny fat'. Ignore it.

liquoricecat · January 2015

By 'skinny fat' I meant more that I realise it's possible to have a healthy BMI with a high body fat percentage. Maybe not exactly the right terminology.

Thanks though. I think I'll take the reading with a pinch of salt next time.

aylajane · January 2015

Absolutely! The scale is pretty accurate for higher body fat percentages. It is not so good once you start building muscle. I went from 40% body fat on it (which I believe was accurate). I got down to about 25% body fat on it (which I believe was accurate), and hit my lowest weight. For the next 8 months I continued lifting weights and focusing on "recomp" fat to muscle. It stayed in the 25-27% range the WHOLE time, even though I could clearly see a difference. My weight stayed about the same as well. I finally went and got a DEXA scan and it said I was at 17%! (I posted about this exact same thing here recently - http://community.myfitnesspal.com/en/discussion/10033546/dexa-scan-one-year-results-have-to-tell-someone/p1 - this is also a good example of being skinny-fat and what that can look like! ugh).

There is an "athletic" mode that might be a little more accurate (it put mine at 21% even though I know it is 17... but still better than 25!). I have mine set on that and just use it as a reference since I know it is inaccurate.

I think at your weight it is likely not going to be helpful anymore. Use measurements and pics instead/in addition to, and/or get another type of scan to confirm. You can also check the Eat, Train, Progress group on here - they have a sticky thread where you can post pictures and they will estimate your body fat for you.

aylajane · January 2015

Didnt realize I apparently deleted the pic - here is a different post instead... The bottom two pics in each are only *15* pounds difference! My aria scale still says 25% on regular mode and 21% on athletic mode.
-

aylajane wrote: »

Top left pic is in 2009 - it was my "before" pic for some diet or workout I was planning to try - didnt make it a week!. In 2011 i had lost 55 pounds very fast and was feeling really good - until I took the top right pic in 2012... UGH... I was *crushed* at how bad I still looked... I was the definition of "skinny fat" - I had lost a TON of muscle... My shoulders and knees were skeletal, I had no butt to speak of, and yet still lots of back and belly fat. I fell into depression and basically didnt get out of bed for months - GAINED 20 pounds...

In late 2013 I joined a gym and got some basic training sessions to help me know what to do. I found I *loved* lifting weights and having someone personally tell me what to do (group classes and videos never worked for me). 4 months of working with him I lost the 20 pounds to put me right back where I was in 2012 - 145 pounds. But a whole size smaller due to gaining some muscle back! That is the bottom left picture.

Two months after that I had lost another 15 pounds, and I have slowly been recomping since with my weight staying steady the whole time. I went from 40% body fat when I started training to 17% (DEXA scan) now. I have curves and a butt and everything The best part is my trainer forced me to increase calories all year. I was paying him, so I listened! I now maintain on 2100-2300 calories a day (yes, it takes some effort). I am actually trying to "bulk" now and gain a few more pounds of muscle! What a change from the past 25 years of my life!

Sorry for the long story, just had to explain the pics!

WRXymama · January 2015

I have my BF measured once a week at the Dr, and I also have the FitBit scale. The differences between the two numbers have been between a 2%-3% difference. Hope that helps.

aylajane · January 2015

WalkingAlong wrote: »

With a BMI of 20, you're not 'skinny fat'. Ignore it.

Yes, you can be. When I first hit 130 pounds (BMI 21.6), I had about 25% body fat. My arms and shoulders were underdeveloped and nearly skeletal looking, and I had no butt to speak of (it hurt to sit down). But my stomach and hips were still clearly bigger. 8 months later, exactly same weight and BMI, but 17% body fat (so lots more muscle!) my body looks completely different. My BMI is still the same. But I am not "skinny-fat" anymore. I still have a lot of excess skin on my stomach and inner thighs and all, so I actually do appear "oddly fatter" than I really am.

BMI doesnt account for body fat percents.

editorgrrl · January 2015

I've had a Fitbit Aria Wifi Scale for a year and a half, and the body fat measurement is complete rubbish. But I love never having to log my weight.

Connect your MFP account at http://www.myfitnesspal.com/apps/show/33

I also use a website called TrendWeight.com to see the trend without all the "noise" from water weight. It even predicts when you'll reach your goal range—way more accurately than MFP's "in 5 weeks" nonsense.

lifeskittles · January 2015

Scales are crap. Really anything to me except the little pod thing is crap...My scale says 24% body fat...then I got one done by a trainer once that said 18%...and then I got one done on another weird gadget that said 15%...and then the body-pod said 21% which I most believe.

liquoricecat · January 2015

Thank you all for your helpful responses. I think I know that my best course of action is to ignore for now.

I was a little shocked by my weight when I first stepped on the Aria - over new year I have indulged slightly but but less than a week ago when I measured myself on my old scales, I was 130 lbs. On the Aria I was 134 lbs yesterday, 133 lbs today. I was hoping the body fat percentage would level out a bit just to make me feel better but nope - still 30% ish. Ah well.

Almost beginning to wonder if my old scales were wrong the whole time and I've actually just not lost any weight at all over the past four months. It's really painfully slow going at the moment...

ohmgetsfit · January 2015

I nearly died when I stepped on it and it said 35%!! (I may take the thing back!! bought it yesterday) But it may be just the challenge I need to even just try to change THAT number...I like challenge...I don't know!

WalkingAlong · January 2015

The body fat scales I had weren't even good for just trend analysis, because they would jump up to 20% for no reason. Yours might at least be ok at judging your overall trend.

If you decide you like the wireless deal but don't want to pay for the body fat tool, I really like the $99 Withings and it's around $80 with a 20% off B,B,Beyond coupon.

editorgrrl · January 2015

liquoricecat wrote: »

Almost beginning to wonder if my old scales were wrong the whole time and I've actually just not lost any weight at all over the past four months. It's really painfully slow going at the moment...

No two scales are ever calibrated the same. Just take the 3-lb. hit on your new Aria, and start looking for a downward trend.

aylajane · January 2015

Google the aria scale and accuracy. Even if you look on the fitbit site they tell you that you can step on it like 5 times in a row before you start to get a consistent number, and others tell you not to do it first thing in the morning because you are more dehydrated (mine is 2-5% different in the evening - weight up, fat % down).

Dont forget to check out the "athletic" mode. THere is no real guidance on who should use it, or at what point you should switch if you have been lifting weights for awhile... But it will put you lower and the site just says "some people get more accurate readings" from that mode.

All still just a guess though!

liquoricecat · January 2015

I changed the scale to the athletic mode and I'm now getting a reading of 27% which isn't great but I'll take it over 30. Thanks all! x

cheritek · November 2015

I know this is an old post, but my aria scale BF% is definitely wrong. It goes up and down 5-7% DAILY. I just ignore it now, but you can also wear socks and avoid the whole thing.

scolaris · November 2015

There's an old thread all about this. The sensors shoot to the hipline; a male/female extrapolation metric calculates the rest. Try telling Aria you're a dude, and see what happens. Some women with leaner lower bodies & broader shoulders get a 'better' reading but even that isn't truly accurate.
I like the visual aids for now. It's pretty easy to determine your range. When I get to my first goal weight I'm going to DEXA (sp?) myself. I've heard university rates for that scan are some of the cheapest.

scolaris · November 2015

But despite this I LURVE my Aria. It is so accurate! My old scale used to bounce up & down which I thought was just normal fluctuation. With Aria that range in any 24 hour period has tightened down to about 18 oz in either direction.

Merkavar · November 2015

It might not be accurate but can't you just use it for long term trends?

Say one month it averages 20% and next month it's 19% the 18%.

You might be 23% in reality but according to the scale your body fat % is going down.

TheopolisAmbroiseIII · November 2015

Merkavar wrote: »

It might not be accurate but can't you just use it for long term trends?

Say one month it averages 20% and next month it's 19% the 18%.

You might be 23% in reality but according to the scale your body fat % is going down.

Usually you can do that, as long as you weigh in first thing in the morning after a bathroom trip and before eating and drinking anything. Also, occasionally you can toss a reading out, like the day after a spat of drinking, or a salt heavy day.

rankinsect · November 2015

Even the professional-quality impedance measurement devices (the ones that use six or eight electrodes and not two) are unreliable. The consumer-grade ones are even less.

They are actually OK for measuring population averages but poor at measuring individuals. Which stinks because each of us is an individual, not a population average.

mrmrsptogether08 · October 2016

i called fitbit customer service because my weight and body fat we're fluctuating each time i stepped on the scale (4 times in a row) he looked into my information and told me it looked like my scale was not calibrated and also asked if i work out (in regards to the BF) i told him i work out 2 hours a day 6 days a week ( 1 hour cardio/ 1 hour crossfit) he stated there's an option to have the BP set for normal or athlete so he changed it to athlete and calibrated my scale. after that he had me weigh myself 3 times in a row to see how it was doing. weight was spot on all times and my BF had dropped 10%. i asked how i could calibrate it myself if i ran into the problem again, he said weigh myself 5 times in a row and the 6th time it would be correct.

AnvilHead · October 2016

Merkavar wrote: »

It might not be accurate but can't you just use it for long term trends?

Say one month it averages 20% and next month it's 19% the 18%.

You might be 23% in reality but according to the scale your body fat % is going down.

Here's a great read about why BIA isn't particularly useful in that way either: http://weightology.net/weightologyweekly/index.php/free-content/free-content/volume-1-issue-4-the-pitfalls-of-body-fat-measurement-parts-3-and-4-bod-pod-and-bioelectrical-impedance-bia/the-pitfalls-of-bodyfat-measurement-part-4-bioelectrical-impedance-bia/

(Read below the heading "What About BIA For Measuring Change Over Time?"

cityruss · October 2016

BIA isn't useful for tracking trends.

Amongst other things, the moisture content or level of dirt on the soles of your feet will throw it off at any given use.

There's simply no way of gaining same state data points to create an accurate trend.

Aaron_K123 · October 2016

cityruss wrote: »

BIA isn't useful for tracking trends.

Amongst other things, the moisture content or level of dirt on the soles of your feet will throw it off at any given use.

There's simply no way of gaining same state data points to create an accurate trend.

That isn't true. Lots of things affect your weight too but you can still use a scale to track your weight over time and from the multiple measurements establish a reliable trend.

BI being innacurate in a single measurement doesn't mean it can't be used to establish a trend over repeated measruements. Sure it might be +5% off one day and -4% off the next but over time that variation will bounce around a trendline and if that trendline is angled downward you are losing bodyfat over time.

Fitbit Aria scale - Body Fat %

Replies

Categories