I decided to constantly measure body fat for myself and use Halo, Fitbit bathroom scale and a highly rated skin caliper. In November and December, I measured early in the morning with the halo and bathroom scale; My wife sewed my skin into four areas with calipers. I measured the body fat of my test subject once with each device.
Our results were similar for men with two different anatomy:
The Amazon product estimated that my friend, a 6-foot 3 man weighing 198 pounds, had 24 percent body fat, the Fitbit scale read 19 percent, and the skin-fold measurement increased to 20 percent.
For myself – 5-foot-6 and about 140 pounds – Halo said in November that I had 25 percent body fat, the Fitbit scale added 19 percent and the skin-fold measurement to 20 percent. In December, Halo said I had 26 percent body fat (alas, I had more than usual leftovers), the Fitbit scale said 20 percent, and the skin-fold measurement increased to 21 percent.
Dr. Cheskin speculated that Halo may have an overestimating bias in its algorithm because underestimating body fat would be more problematic for an obese person.
Amazon’s medical officer working on Halo, Dr. Maulik Mazmudar said that people should expect the results of the device to vary as the method was more accurate than body fat content and calipers.
He said that Amazon developed its body measuring algorithm from a sample set of thousands of thousands of body images from a wide range of demographics. Amazon then conducted internal tests measuring people’s body fat using technology that uses halo scanners, smart bathroom scales, and DEXA, X-rays. Scan for bone density, Which has been found in the study to be a reliable remedy for body fat. It found that the halo method was twice as accurate as the bathroom scales.
Nevertheless, Drs. Cheskin was unaffiliated with Amazon’s accuracy claims. He said that a validated study would include clinical trials measuring body fat of many human subjects with each method – HALO, DEXA, bioelectrical impedance scales and calipers – and comparing the results side by side.
Accurate or not, the most disappointing part of Amazon’s body fat analysis was that it lacked critical context. Even though the app asked about my ethnicity, age and gender, it said that my 25 percent body fat level was very high and well outside the “healthy” area (about 12 to 18 percent). It also stated that healthy outcomes were associated with longer life and lower risk of heart disease.
Dr. Cheskin offered a more nuanced analysis. Body fat levels may have different health effects depending on your age, ethnicity, gender, cholesterol levels, and family history. Waist circumference matters a lot, as severe abdominal fat can be associated with health problems.