I don&#x27;t trust the absolute numbers, but the data from my FitBit Aria has a pretty low variance over time:<p><a href="http:&#x2F;&#x2F;imgur.com&#x2F;5AgKU9F" rel="nofollow">http:&#x2F;&#x2F;imgur.com&#x2F;5AgKU9F</a><p>It does seem to be tracking reasonably well - I&#x27;ve lost a bit of fat, but not a significant amount since then. Given what I see in the mirror, I think 16-17% is about right. There are some weird fluctuations, but we&#x27;re talking 1-2% day to day. The range of the graph is about 4-5%.<p>The trick is to measure several times a day if you get the chance (or at the very least when you get up and when you go to bed) to smooth out any fluctuations.