My mother in law is an ex-obese person. When she went to Disneyland she had to use the scooters because she was too fat to walk.  Seriously.  That is not a joke. Anyway, she got lapband surgery to make herself throw up or shit herself when she over-eats and has since gotten to a more normal, if still not fit, weight.  She recently bought a fitbit and wears it all the time.   Last weekend she came to visit and said "I walked over 4 miles so far today!  I don't even know how I did it!"  I just wanted to tell her that she probably did not actually walk 4 miles while sitting at her desk at work and then driving 5 hours to visit but I couldn't bring myself to break her heart. Fitbit is just another excuse tool for people to avoid working out.  If it tells you that you "walked" 5 miles during the day it's a lot easier to tell yourself that you can skip the gym even though you spent all day at the office, in the car, and then on the couch at home.