This has been done for years, but is just getting attention.  A hospital health policy (which I will not name) implemented this almost 10 years ago.  Their approach was that the hospital substantially increased their health premiums, but an employee could receive 'discounts' for 'positive' behavior as defined by the employer - no smoking, within a certain weight and body mass, etc.  So essentially it was a reverse penalty for employees.  If you refused, then of course the employee paid the higher insurance premium.  There was voiced opposition when this was implemented for the invasion of privacy, but 'for the good of all' it was done.  Privacy is becoming a thing of the past.