The site seems to be showing that it has gathered a lot more than just eating and burning calories, safe to say such intensive data can be used to correlate with certain standard illnesses to be cautious.
Your data over a period of few months might make more sense to understand what ill-effects certain things have had on you. Think about 1 year's worth of your data being analysed to tell what certain things have had certain health related changes in you. Of course it still would take time to know how the changes you make will change things in you but based on your past data it could predict perhaps?