Body fat fitbit readings

Where is your fitbit getting data on body fat? If you have linked a "smart" scale, the problem is that impedance-measures are pretty useless (the "body fat" estimate varies according to hydration level). Just ignore it.

Your Fitbit can't measure BF. It sounds like you're linked to a bioimpedence scale...those aren't accurate either. At best they can give you an overall long term trend that is somewhat reasonable, but bioimpedence scales aren't accurate for measuring BF as there are too many factors that can impact electrical current flow. Consumer Reports won't even review them anymore due to their complete unreliability.

I'm guessing you use a Fitbit Aria scale? I have one of those and I pretty much ignore the number. I heard it can be useful for overall, long term trends, but it really isn't reliable. It had me sitting at 18 to 19% BF for a while and I had this big drop recently where I thought I was maintaining 112 to 113 pounds but now I'm between 109 and 110. Since the drop, my BF readings have been 15 to 16% and on the first day of the drop it was 13%. I'm pretty lean but I'm nowhere near 13% BF; that's essential fat level for a woman. If I had a DEXA scan, I would guess I'm 19 to 21% BF.