In response to the second post i would like to say that i agree with you. I also believe that lots of employers have already taken note that healthy work environments promote more worker productivity. And i believe that lots of employers these days are making a real effort to promote a healthier workplace. Many companys these now offer bonuses based on company or individual progress, or other kinds of benefits such as free gym memberships and company outings.
I believe that the leading cause of low productivity in the workplace is worker dissatisfaction due to unfavourable work conditions, such as to many hours or having too much of a work load or maybe poor working conditions. If an employer were to notice these things and really do something about it, worker productivity would improve.