It seems self-evident that the most effective weight loss will be from people who have found the will to do so within themselves, but the point of a tracker is to *give* some additional incentive to someone who would otherwise not have done the work at all, or may have stopped substantially sooner, lacking an unambiguous, objective, and quantitative measurement of how much work they have actually done.
For truly fair comparison, one should evaluate how much weight people with a weight-loss tracker lose compared to the average person who may not even exercise at all.
That's a pretty fucking stupid sentence to write. How is that a fair comparison? People trying to lose weight vs not? Let's take a measure of people trying to stay alive vs people trying to kill themselves. That's about as useful of a measurement. Dead people lose weight much faster than live people. Go to bed. Sober up. Stop posting for a while maybe?
The difference between a career and a job is about 20 hours a week.