10% difference in BF% results?

Caliper test results can be heavily scewed by user error. Handheld electronic analyzers results can be heavily scewed by hydration levels.

I trust my scale and handheld monitor.

well you shouldn't

Changes in body composition during weight loss in obese subjects in the NUGENOB study: comparison of bioelectrical impedance vs. dual-energy X-ray absorptiometry.

Verdich C et al. Diabetes Metab. 2011 Jun;37(3):222-9.

"RESULTS:

At baseline, BIA significantly overestimated FFM and underestimated FM (by 1-3 kg on average) compared with DXA, and the limits of agreement were wide (mean ± 7-8.5 kg). "


A comparison of dual energy X-ray absorptiometry and bioelectrical impedance analysis to measure total and segmental body composition in healthy young adults.

Lehy S et al. Eur J Appl Physiol. 2011 May 26

"BIA was found to underestimate the percentage total body fat in men and women (p < 0.001). This underestimate increased in men with >24.6% body fat and women with >32% body fat (p < 0.001). Fat tissue mass in the trunk segment was overestimated by 2.1 kg (p < 0.001) in men and underestimated by 0.4 kg (p < 0.001) in women. BIA was also found to underestimate the fat free mass in the appendages by 1.0 kg (p < 0.001) in men and 0.9 kg (p < 0.001) in women. Compared to dual energy X-ray absorptiometry, bioelectrical impedance analysis underestimates the total body fat mass and overestimates fat free mass in healthy young adults."

and James Kreiger's excellent write up on bodyfat testing methods

http://weightology.net/weightologyweekly/?page_id=146

http://weightology.net/weightologyweekly/?page_id=162

http://weightology.net/weightologyweekly/?page_id=175

http://weightology.net/weightologyweekly/?page_id=218

http://weightology.net/weightologyweekly/?page_id=283

well you shouldn't

I do. Trust what you want to trust.

not sure what you have against science and accuracy, did you look at the 2 studies i posted?

also

I’ve heard people make the argument that, while BIA may not be that accurate, it should work fine when tracking change over time. The theory, they say, is that the error should be the same each time you use it.

The problem is that this isn’t true. As I mentioned in the article on hydrostatic weighing, the density and hydration of fat-free mass can change with weight loss. If this can affect the accuracy of hydrostatic weighing for measuring change over time, then you can be sure that the effect on BIA outcomes is going to be significantly larger.

Researchers have looked at the accuracy of BIA for tracking body fat change over time. In one study, the disagreement between BIA and the 4-compartment model ranged from -3.6% to 4.8% for measuring change. This means you could lose 3.6% body fat, but BIA would show no change. Or, BIA could tell you that you lost 8.8% body fat when you really only lost 4%. In fact, in this study, plain ol’ bod mass index (BMI) did just as well as BIA for predicting change in body fat, except for in one person.

BIA can be problematic because it’s a prediction based off of a prediction, so the error gets compounded. When you look at group averages for BIA measurements, there tends to be bias, with BIA often underpredicting how much fat you have. As with other techniques, the individual error rates can get high, with some research showing error rates of around 8-9%. In fact, BIA doesn’t do much better than BMI at predicting body fat in some cases. When it comes to measuring change over time, BIA can often underpredict the amount of fat loss, and the estimated change can be off by up to 8%.

http://weightology.net/weightologyweekly/?page_id=218

If you refuse to change your beliefs despite mountains of evidence to the contrary, why should anyone listen to anything you have to say?

Everyone has a free will. I'm not making a person believe anything that I have said. If they do, they have done so on their own.

question: do you believe the Earth is flat?