To your first point -- some people do need to control their weight (or even lose weight), not everyone is in the same category with regards to health/weight/etc., And to be quite honest, I'm pretty sure last time I saw my doctor they told me "it'd be a good idea / healthy to lose X pounds..." -- that's fairly cut and dry to me, I need to lose some weight -- this service is just a method of tracking that progress while offering up helpful advice along the way.