It is hard to believe that there is an academic journal is that completely dedicated to Health Games research. It really shows the high level of interest people have in this area. The underlying idea is that, if people can spend hours and hours performing mundane chores in games like Famville, why not have them perform other mundane chores that are actually good for their health. The trick is turn those mundane chores into some kind of addictive game, and that is one of the key focuses of "health games".
So far, no one has figured out a winning formula to build addictive "health games". But many experiments are underway to test different models of game mechanics and health promotion theories. That is basis for a vibrant academic research field. For more, please check out the editor-in-chief Bill Ferguson's summary article: Games for Wellness—Impacting the Lives of Employees and the Profits of Employers.