[miki123211]

You don't, but you provide lower insurance prices to those who can demonstrate a healthy lifestyle.

You wouldn't even need too much surveillance to do this. Give people a yearly "fitness checkup" to encourage physical exercise, monitor weight to encourage healthy eating habits, do periodic drug tests to discourage drug use etc.

If you combined this with a (privacy preserving) fitness band that would monitor your vitals, and only send a list of premiums you're eligible for, you could do even better.

You'd have to account for preconditions that make it hard/impossible to exercise, but this would work for most people.

[int_19h]

Any actual, real-world implementation of such a thing would 1) not be privacy preserving (except in the "we pinky promise we're not going to use this data!" kind of deal), and 2) would inevitably expand the definition of "unhealthy lifestyle" over time as a way to exclude undesirables from the system and thereby leave more resources for those who remain.