For years they encouraged workers to improve their health and productivity with free screenings, discounted gym memberships and gift cards to lose weight. More recently, a small number charged smokers slightly higher premiums to get them to quit.

Results for these plans were lackluster, and healthcare costs continued to soar. So companies are taking advantage of new rules under President Barack Obama's healthcare overhaul in 2014 to punish smokers and overweight workers.

Some will even force employees to meet weight goals, quit smoking and provide very personal information or pay up to thousands more annually for healthcare.