Hi,
I am curious about the accuracy, reliability, and validity of the various scales that have you input whether you are male/female and age, and how it determines %BF.

The scale I have at home is consistently 2% or 3% lower in reading my BF% than at my trainer's gym. The weight seems to be the same however.

I understand the fact that the scale sends a current through your body and estimates it based on an algorithm, etc., but has anyone done a caliper/scale comparison. If so, what have you found?

M

I never trust scales. They're only good for weight. I think the bf% feature is a gimmick.

Buy yourself some calipers.



Hi,
I am curious about the accuracy, reliability, and validity of the various scales that have you input whether you are male/female and age, and how it determines %BF.

The scale I have at home is consistently 2% or 3% lower in reading my BF% than at my trainer's gym. The weight seems to be the same however.

I understand the fact that the scale sends a current through your body and estimates it based on an algorithm, etc., but has anyone done a caliper/scale comparison. If so, what have you found?

M

I have one of those Tanitas, and I also have calipers. I notice that my BF is different by 3-4% if I measure immediately after waking up and if I wait 1-2 hours, even though I haven't eaten anything yet. The manual even mentions the fluid distribution in your body affects the reading.

The calipers are comparable to the Tanita. The stomach measurements vary the most (for me) dependng if I've drank or eaten, because my tummy is swolen & I can't get as big a pinch.

I wouldn't put a whole lot of stock in any BF% reading from a scale. I second tennisball--get some calipers. Even the cheapest set you can buy will get you a more reliable reading than a scale.

I don't think my Tanita scale is very accurate (maybe for my legs, but not my whole body), but I average it in with my FatTrack calipers, MyoTape Navy, and MyoTape YMCA readings to get an average that I think is pretty good.

All the readings but the Tanita track evenly. When there is a bump or a drop in one you can see the same thing in the other. The Tanita has shown a downward trend but it doesn't track evenly with the other measurements.

Also as others have said, you should use the Tanita at the same time each day under the same circumstances (same water consumed, etc.).

I don't have a gym so I can measure my BF, but I do have a Tanita. Though there is a +/-3% error rate for the BF, it's consistant. Meaning you won't be 16% one day and 10% the other.

Here is something from their web site to get you the closes possible and for me it mirrors what I see with other online BF calculators so I'm pretty confident with it.

Here is something from the Tanita website that helps with getting an accurate reading

"Q: "Are there optimal conditions for determining body fat percentage using Tanita products?"



A: Yes, these are as follows:



Select a consistent time of day, and stick to it.

With an empty bladder.

When normally hydrated (generally between 5-7pm before evening meal).

Unclean footpads may interfere with conductivity.

Nylons interfere with conductivity. If it is absolutely necessary to measure in nylons, use a drop of isopropyl (rubbing) alcohol on the footpads to act as a conductor.


Things that can affect hydration include:

Strenuous exercise.

Recent food intake.

Diuretics such as caffeine, alcohol, certain medications.


Early morning is not recommended because the body is often dehydrated after a night's sleep. Once you have established your baseline, Tanita recommends monitoring body fat about twice a month. Checking body fat more frequently is not beneficial as changes occur slowly over time. "