Findings from a recent Hewitt Associates survey determined employers depend on both penalties and incentives to encourage their employees to participate in wellness programs. Furthermore, the number of employers using penalties is on the rise. Nearly half of employers use financial penalties or are planning to use them in the next three to five years.

Over 80 percent of employers said they were raising their non-participating employees' premiums, by far the most common penalty. Two-thirds of employers penalize workers for smoking, and half implement fees for not participating in disease management programs.

"As companies learn more about their workforce, they're realizing that some people may be more motivated to take action if they risk losing $100 versus gaining $100," said Cathy Tripp, a principal in Hewitt's Health Management practice. "The key for each employer is to find the right mix of strategies and plan designs that will motivate employees to be healthier, but not go so far as to drive the wrong behaviors."