FitBit Aria scale – body fat measurements aren’t accurate

June 08, 2016

FitBit Aria

My method of measuring body fat is flawed.

I am using the FitBit Aria. The Aria is a wi-fi smart scale that is generally pretty awesome. It tracks both my weight and body fat. All I have to do is step on each morning and it recognizes me (vs my wife) and it pushes all my data to my FitBit and MyFitnessPal accounts. At face value this is really a perfect scale being that I am more concerned about fitness than just my weight. After all if I was 220 lbs (which is technically obese) but had 6% body fat, I would be a happy camper!

Here’s the problem. I am 1 week into my new challenge. I have been losing weight each day. Oddly though, my body fat has gone up.

Day 1: 24.3% fat (202 lbs)
Day 9: 24.4% fat (194.8 lbs)

While I admit that I am likely losing some muscle. My weight loss is too fast to not lose some. However, I refuse to believe that I am gaining body fat.

I am continuing to lift hard 5-6x a week. I am losing weight, some of that must be fat.

One reason the scale may be giving me off readings is because I am in ketosis. This is causing my body to shed water and make the body fat readings less accurate. Now that I think about it I haven’t been tracking how much I have been drinking very closely.

I did some research and it looks like these types of scales aren’t terribly accurate. They can fluctuate depending on the amount of water in your system.

Now what?

I will keep using the scale each morning. I will also keep track of my drinking more closely.

The mirror and a trusty tape measure will tell the truth. Hopefully the scale will keep up! ;)