For example, employees who have used tobacco in the past year and aren’t enrolled in a cessation program may pay up to 50 percent more than their co-worker who doesn’t smoke, if their company participates in one of these wellness programs.

Business groups have supported the increases in penalties for “unhealthy” types in part because it offers a way to shift the cost of medical care to employees who, the thinking goes, aren’t as proactive about their health and are therefore more likely to ratchet up the cost of health insurance for everyone. Proponents of such programs point to estimates by economists at Harvard that show a $3.00 return for employers for every dollar invested in the programs.

“We applaud and support this expansion,” the Business Roundtable wrote in a letter referencing the higher penalties, quibbling only with the fact that it offers too many outs for employees who can’t seem to meet a wellness goal.

But recent research has poked holes in the theory that wellness programs reduce healthcare costs or encourage employees to change their behaviors. In fact, some consumer advocates have said that employers’ connecting insurance premiums to factors like weight loss might end up hurting the least-healthy employees by making health insurance pricy for those who need it most.

“The increased cost of a plan for someone who is unable to meet a specified wellness program outcome could make the plan unaffordable and potentially create a barrier to health coverage,” said Dick Woodruff, vice president of federal affairs for the American Cancer Society Cancer Action Network.

Just over half of employers with more than 50 employees offer a wellness program, and over the past few years, the percentage of companies offering health-insurance discounts to employees for participating in such programs has increased, according to a survey of 600 executives by the Society for Human Resource Management. In 2011, 12 percent of employers offered premium reductions for employees taking part in smoking cessation programs, and 7 percent did so for weight-loss programs.

But whether employees sign up for the programs is a different story. A study by the Rand research institute released in May found that fewer than half of employees at offices with wellness programs undergo clinical screenings and assessments, and less than than 20 percent take part in either weight loss or smoking cessation programs.

Employees who did head to the nearest gym or Prancercise track at their employer’s behest did lose weight—but only about a pound a year over the course of three years, Rand found. Those lackluster findings were bolstered by another study from the University of California, which showed that “participating in work-based wellness programs does not lower blood pressure, blood sugar, or cholesterol and rarely leads to weight loss,” Reuters reported. And just 2 percent of the employers Rand surveyed had reported measurable cost savings through the programs.