I think that Fitbit and other fitness wearables don’t fall under devices to be regulated by the FDA. The reason being that they aren’t truly medical devices as they don’t make any medical claims. As a general wellness product Fitbit is marketed towards improving a persons physical health and fitness rather than claiming to help treat or cure some kind of disease or condition. Fitbit is also a very low risk device as it is not invasive and doesn’t threaten the well being of the person using it.