Question about Scale w/ Body Fat Measurement

[jsj0305]

OKay I have a question. I have the body fat measurer thingy on my scale....you step on the scale on these feet looking metal things and it weighs you and gives you your Body Fat Percentage and weight.

When I started Atkins at 190lbs, it was reading 40.5%

This morning when I weighed in at 161.2 , it said 40%??!!?? It always sticks around 40%, sometimes 39.6%.

I am losing fat, I can tell. MY whole body is a lot less jiggly and I exercise and my muscles are more defined. I eat the right foods, I drink my water, and I take my vitamins, so I know better than to think I am losing muscle mass.

My question is are these things always accurate?

[dotsamantha]

Re: Question about Scale w/ Body Fat Measurement

They use bioelectrical impedance to measure the body fat and have a great variance.For instance, the amount of water in your body, your skin temperature and recent physical activity can all adversely affect the results.So only by following strict rules can you hope to get an accurate measurement of your body fat using these scales. The most important rules to observe in order to make a more accurate calculation of your body fat are:

• Don't eat or drink for 4 hours before the body fat measurement test.
• Don't exercise for 12 hours before the test.

Notes:

• Some studies have shown variances as high as 8 percent when using the bioelectrical impedance method even if the rules are precisely followed.

I have one. I try to do it only first thing in the morning, but after I've had some water.

[jsj0305]

Re: Question about Scale w/ Body Fat Measurement

Hmmm, I do it first thing in the morning before I eat or drink anything. I don't exercise 12 hours before either....

Perhaps I was just MORE than 41% and it doesn't go that high and now it is dropping! *LOL* I am 161.2 pounds and 5'2 1/2. That's a LOT of fat! LOL

Thank you so much for posting all of that great info, that was so sweet of you

[2big4mysize]

Re: Question about Scale w/ Body Fat Measurement

actually hydration plays a very important role in the accuracy of your scales and your instuction manual should have informed you to do it in the evening when you are well hydrated.

We are dehydrated in the morning from not drinking water and from losing moisture through our skin and exhaled air.

[big_bad_john]

Re: Question about Scale w/ Body Fat Measurement

You just wait until you dropped another 20...it'll go up to 50%!!!

Helpful John

[ValidRouge]

Re: Question about Scale w/ Body Fat Measurement

the book that came with mine says to weigh in the evening because your body is hydrated (as 2big said). As a matter of fact here is what the pamphlet with my scale says:
"Bioelectrical Impedance Analysis is a safe, low-level electrical signal passed through the body, and body fat percentage is calculated based on the amount of impedence as the current flows from one point to another. The signal passes much faster through lean muscle than fat because muscle contains 70-75% of the body's water (fat contains almost no water). BIA is most consistent and reliable if you are properly hydrated and if you wait three hours after eating or exercise before the measurement."

Ive weighed a few days in the morning and a few days in the evening, and here is what I've found Consistently:
1)when I weigh in the morning, of course my weight is lower. But my total body fat is in the low 40's and my total body water is sometimes below 40 (too low).
2) when I weigh in the evening, well, my weight is higher. BUT my total body fat percentage drops into the mid 30's and my total body water goes up to like 45-47% (which is in the healthy range for water % according to the charts with my booklet).

It has to do with the hydration in the muscles. Since you store water mostly in the muscle tissue (not in the fat) when you are dehydrated (in the AM) the scale can't tell what's muscle and what's fat...thus the higher total body fat percentage.

What does this mean for me? Now I'm a scale addict TWICE a day!!

[dotsamantha]

Re: Question about Scale w/ Body Fat Measurement

That's why I wait a bit, after water and maybe breakfast. I don't think they're very accurate (for me) anyway. I use it more for the scale.

[jsj0305]

Re: Question about Scale w/ Body Fat Measurement

Awesome, that's exactly what I was looking for. I just checked and got 38.2% That's a little better , LOL.

Thanks so much for all the great info!

[SugarFreeSheila]

Re: Question about Scale w/ Body Fat Measurement

The few times I have tried these body fat scales, they are about 8-12% off what my body fat really is.

[2big4mysize]

Re: Question about Scale w/ Body Fat Measurement

remember we don't really need it to be exactly accurate as we are losing weight what you need it the positive reinforcement and validation it gives you that YES fat is being shed even when sclae weight number doesn't move. just compare this weeks numbers with next weeks numbers done at the same time iof day. you can even use your AM weight as you pounds number and your PM body fat % as the amount of those pounds lost that were fat. happy low carbing.

[jsj0305]

Re: Question about Scale w/ Body Fat Measurement

Thanks sheila and 2 big. I do by how my clothes fit and how I feel, but the number alarmed me. I am so glad you guys helped me to figure this one out.

[Analog6]

Re: Question about Scale w/ Body Fat Measurement

This is fascinating. I just got mine, and the first time I used them (after dinner when I unpacked the box!) it said 44%. SInce then I have just had a quick weigh in the morning to check my weight.

I'll have to do the body fat one again soon in the evening.