I think part of the problem is that people think of as "go to gym x number of times, shed x number of pounds". It becomes a short term and very result oriented

I think part of the problem is that people think of as "go to gym x number of times, shed x number of pounds". It becomes a short term and very result oriented solution. If and when it doesn't work (because creating a formula that works for everyone across the population is very hard) people become demotivated and give up. If you could come up with a way of making people view movement as fun and enjoyable then they would probably have a better time of it. Not to get sentimental, but look at kids in a playground - run, jump, climb....and they just have fun playing catch or exploring a climbing frame or jumping from here to there. So there's a startup idea - playground for adults - adult sized swings, roundabouts, climbing frames and trampolines.....get the adults to play like kids. Change their motivation from "weight loss" to "have fun" and they will more likely stick with it.