After you first setup the FitBit Aria and weigh yourself, you may notice that it only displays your measurement as “Guest”.
To get it to recognize you, you’ll need to log into your FitBit.com dashboard and assign the measurement to your account.
Here is a screenshot of the menu at the top-right of the Dashboard after you have logged into your FitBit account:
Click on the “Aria Scale” menu option. That will give you the screen below:
Under the People column, you should see measurements for “Guest”. Change those to the appropriate account by clicking on the button and choosing the correct account from the drop-down.
Now, go to your scale and weigh yourself again. It should register you as “Guest” one last time, but this time, it should prompt the scale to go into “Update” mode. Once it is finished updating, you should be associated with your account. Now try to weigh yourself again. It should now measure your body fat percentage and then display your initials on the scale.