body fat weigh scales..

[914cophopefulNY]

i have a scale that measures weight body fat percentage and water percentage.. the type of scale is a Tanita.... now when it calculates it does it do it based on an average when u put your age, height, and if you are athletic or not in? or does it actually sent a pulse through your body and measures muscle, organ, and bone weight and all that? i did it last week and it said i weight like 177 and my body fat was 25% then tonight i did it and i weight 176.4 and my body fat was 17.8% ... you think it matters if you ate in past couple of hours and all that? just trying to get opionons of others

[RexForest]

According to tanita.com:

"Proper hydration is essential for life. Maintaining a healthy body water % improves overall health and keeps you feeling energized and operating at peak performance. Tanita’s new Scale plus Body Fat monitors with Body Water % calculate body water levels using bioelectric impedance analysis (BIA), the same highly accurate method used in all our body fat monitoring products. BIA monitors body water % by sending a safe, low-level electrical signal through the body. Our body water scales are the first of their kind available for in-home use."

[914cophopefulNY]

so i guess that basically means i lost 10% body fat in a week? lol i doubt that my water percent was 58% and 17.8 body fat so idk.. doesnt seem kosher to me

[SA13]

or does it actually sent a pulse through your body and measures muscle, organ, and bone weight and all that?

Because different matierials have different resistance to electical current the scale attempts to estimate body fat based on the resistance the current experiences when passing through your body. Your weight and height are needed to make the estimation more accurate.

Dehydration makes the readings slightly higher when using impedence testing to estimate body fat. In general impedence testing is considered to be accurate within approximatley 4%. The water dunk method is considered to be accurate within 2-3%.

I'd guess there was something else besides hydration levels going on with your body, the scale, or both for the reading to be that diffferent.

[itnstalln]

Because different matierials have different resistance to electical current the scale attempts to estimate body fat based on the resistance the current experiences when passing through your body. Your weight and height are needed to make the estimation more accurate.

Dehydration makes the readings slightly higher when using impedence testing to estimate body fat. In general impedence testing is considered to be accurate within approximatley 4%. The water dunk method is considered to be accurate within 2-3%.

I'd guess there was something else besides hydration levels going on with your body, the scale, or both for the reading to be that different.

BEI testing is probably only within %4 on its best day with very expensive equipment. A 40 dollar scale is probably +/- 7-10% You can get skin fold calipers designed to be used by yourself to measure. If you follow the directions, this is probably your best bet for measuring yourself regularly. If you don't follow the directions even the skin fold will be way off.