I use a Tanita body fat scale and recently my weight has been kind of on a plateau. But I have noticed that my body fat percentage seems to be creeping down-- but it's kind of hard to tell.... because it fluctuates.

Is there a rule of thumb about the best way to assess the most accurate BF%?
Are those Tanita scales relatively reliable?

My BFP used to be about 45%, and now, most of the time, it shows 42%... sometimes it drops to 41% sometimes it bounces back up to 44%.

Is there any kind of normal relationship between body fat percentage loss and weight loss? Is there any rule of thumb about whether I'm trending in the right direction or holding on to LBM as I lose?

Thanks!

Hi Ubergirl.

Fantastic weightloss!

The gold standard for BF% currently is a DEXA scan. Not really a convenient option but just an FYI. If you are due for one anytime soon, inquire about your BF% when you have your bone density checked.

BIA, or Bioelectrical Impedance is a more convenient method. It is based upon the notion that fat free mass is a good conductor of electrical current (muscle contains around 73% water) while fat is anhydrous, a poor conductor of current.

Factors that affect your BF reading is eating, drinking, or exercise prior to using the tool. The best time to get your BF reading is the first thing in the morning after you visit the bathroom. If you have a drink of water before taking the measurement it may artificially give you a lower BF% reading.

I get various readings when I take my measurements too. I look at it as the variance in hydration levels from one day to the next. Mostly I look for an overall trend downward just like every other measurement we do.

As a side note: the Tanita scale has been found to overestimate BF% when compared to the Omron hand held device. I don't know if it is a significant difference or even how much.

Anyway, just do the measurement first thing in the morning after you use the bathroom and forget about trying it any other time of the day. Once you eat, have something to drink, or start to move around throughout the day your readings could be off as a result.

I still think the best measure of success is the pant-o-meter...but that's just me.

Thanks! That's great info. I usually do my weigh in the morning, so I think I'm definitely trending down a bit.... I'm glad to know about the DEXA. I've never had one for bone density, but I'm probably old enough to justify it.

True about the pants-o-meter...! Haven't dropped a size recently, but I've noticed that they fit me differently now, riding down on my hips instead of up at my belly button.

There's another problem with bioelectrical impedance...

Aside from the fact that all circumstances should be equal (which is almost impossible given all the factors that lydia227 explained), the other thing is that the scales that you stand on predominantly measure lower body fat percentage, while the handheld scales predominantly measure upper body fat percentage.

This can distort the measurement as well.

I prefer skinfold measurement. But you have to have someone who's skilled at it do it, and you should try to keep circumstances equal as well. It's not as convenient as the scales though.

Clothes and the mirror (or photographs) are good measurement tools as well ;-)

I go to a doctor who has a bioelectrical impedance scale that uses both the scale base and grip handles to assess. My scale at home has only the scale base. I was surprised to find that each time, my scale at home gives me 5% greater body fat than the one at the doctor's office.

I have one of those scales same brand and it drives me CRAZY I am what I think pretty lean I work out several hours aday and have for years. am at goal no fat on my body and it show 32% when I weighed 50 lbs more did not work out at all and had blubbery fat it said 35%?????????????????

I have a Tanita scale, an Omron handheld and a measuring tape. Every time I weigh I do the Tanita and the Omron. I find the Omron to be more consistent than the Tanita. I also use the navy circumference method (based on neck, waist and hip) and for all weights from ~ 190 to 125 lbs for me it was within 1-2 % of the omron and the scale. Whenever I measure I make sure I get all 3.

My Tanita used to track the omron very closely and isnt right now which makes me think my scale might be on the way out (the omrons #'s make more sense). FWIW the omron and the navy circumference track together

Devadiva - does your scale have an athlete setting? They really give screwy measurements if they dont.

Since I have both and have been testing every day this past week...

My Tanita reads usually 1-2% higher but is FAR more affected by hydration and other factors. The days following my marathon I had ~3 lbs of fluid retention from sore muscles and during that time frame the Tanita read 2% LOWER than the omron, but when the water flushed out it went back to reading higher.

I also had 1 day that my weight was WAY down so I may have been a bit dehydrated and that day the Tanita read 4% higher than the omron.

In the 8 days I have used both the omron has ranged from 29.3 to 28.6%. The tanita has ranged from 27.7(day after marathon) to 32.3 (low weight day) with the bulk of the days being 30.2-30.8%

Thanks for this thread...I hadnt paid attention to what was causing the Tanita to vary...interesting..maybe my scale isnt dying.

Personally, I find a tight pair of jeans and the way my abs and arms look to be the best measure.

My scale does't have any setting except to put in your age and sex and thats part of what gets to me I am 57 actually in a few short weeks 58 and if you play with my age it really drops!I would ignore it but its the kind that tells you every time you step on it. I have two homes and have one at my other home also and get the same high readings. I have a nerve disorder in my hands and feet and I sometimes wonder if that gives it a wacky reading OR maybe it was just my poor habits before I started working out and eating clean which I have been doing for quite awhile now should have caught up by now,I HAVE A PICTURE of me under LIVING MATIENCE...FAT PANTS it was from end of last summer and I am actually leaner now I can't remember how to post pictures need to figure it out again.I weight lift everyday and do INSANITY.

I am so glad today that i have my scale and my omron. I've been hitting it hard and my weight isnt budging but by all 3 methods of fat calculation (tanita, omron, navy circumference) I have lost 2-4 lbs of fat. Waiting for the water wooosh now.

The navy circumference comment got me googling. I found a cool calculator with charts!!

http://www.scientificpsychic.com/fitness/diet.html

I just tried the navy circumference measurement, and it gives me a BF % about 3% lower than my Tanita, even though I added an inch to my waist measurement just to be on the safe side.

Interesting.

Uber, my measurements add up exactly to what the hand held device at the gym gives me.

Yeah, navy measures a little lower for me, but not too much lower and the delta when things change is about the same. Tanita reads higher than omron reads higher than navy right now.

I think it is still a good metric if you dont have any electrical impedance measurements.