At one point one of the administrators (I think) posted that sleep is already taken into account.
However, when I put my sleep in as an activity, the numbers all track really closely to what I am losing. Some folks have commented that the activities calories burned seemed too high, so I started off adding sleep in and have been doing so for 2 months.
You may have to do a period of trial and error to see what works best for you. Too bad we can't plug into something and have it tell us exactly what we eat and what we burn...it's an estimate at best.
And now that you don't have to be perfect, you can be good.