This 2014 photo shows the tobacco in cigarettes. A survey from the Kaiser Family Foundation found 36 percent of large businesses and 18 percent of small businesses offer some form of financial incentive to participate in company wellness programs. One company in Maryland gives workers $250 to quit smoking. (Matt Rourke/AP)

If you’re fit and you don’t smoke, get a job at the Nuclear Energy Institute and you’ll get a whopping $500 off your annual health insurance premium. How do they enforce it? An employee’s body mass index is measured directly, and smokers are expected to operate on the honor system.

“In a small organization we know who the smokers are. You see them when they go and smoke and they can’t get away with it,” said Lori Brady, a senior manager at the institute.

Provisions of the Affordable Care Act directly encourage these incentives — the inducements are legally allowed to be up to 30 percent of an employee’s monthly premium, up from 20 percent before the passage of the law — and the idea has been mainstream for years among business and human resources leaders. A survey from the Kaiser Family Foundation found 36 percent of large businesses and 18 percent of small businesses offering some form of financial incentive to participate in company wellness programs. A separate survey of 121 large companies by the National Business Group on Health suggests that the incentives are even more common among ultra-large firms, and the bigger firms offer bigger incentives: Of the surveyed companies with more than 20,000 employees, 88 percent offered incentives, and the average size of the incentive was nearly $900 annually. Many of these companies tie the incentives to a biometric test, literally paying their employees for improvements in body mass index or blood pressure.

But despite their ubiquity in America’s workplaces, the way these incentives are being rolled out is changing. Human resources managers still use them, but they’re less keen to play corporate nanny. Many now offer them as part of a broader wellness program.

“There has been a ‘wellness’ backlash,” said LuAnn Heinen, vice president of the National Business Group on Health, a health-care consultancy. “Biometric screenings ask about helpful things, but they don’t do it in a very nice way.”

But if the incentives are usually positive, why all the griping? When would employees object to being paid extra to do something that improves their health?

“If you start introducing all these carrots and sticks, it really sends the wrong message,” said Janet McNichol, human resources director at the American Speech-Language-Hearing Association. “That sort of Big Brother-ish tone doesn’t send a message that you care about your employees or you’re treating them like adults.”

Some companies prefer to choose the carrot over the stick, offering one-time payouts rather than differentiating premiums based on health status. Iron Bow Technologies, an information technology company with 240 employees based in the company’s Chantilly, Va., headquarters, offers cash reimbursements of up to $300 for those who buy smoking-cessation products. Insurance Associates, a 50-employee Rockville, Md.-based company that sells construction insurance and bonds, takes the incentive a step further: The company already pays 100 percent of employees’ premium costs, but it will give workers a $250 check to quit smoking.

Praxis Engineering Technologies, a mid-sized company based in Annapolis Junction, Md., will pay an employee up to $300 to get an age-appropriate check-up, and another $300 if they take their spouse.

“I want to make it a positive experience as opposed to telling someone, ‘You’re a bad person for not going to the doctor.’ I don’t want to make it negative,” said Debbie Mobley, human resources manager at Praxis.

Other companies solve this problem by designing their wellness programs to fit around what they already know about their employees. After recognizing that much of the office was vegetarian, the National Retail Federation challenged employees to go vegan for three weeks and held before-and-after health tests measuring glucose, cholesterol and blood pressure levels to give employees a sense of whether the diet worked. There was no financial incentive for health improvement, but the company says a number of employees adopted veganism on their own as a result of the challenge.

“People like this stuff. And they’re pleased that their employer thinks highly enough of them not just as another cog in the wheel,” said Kerry Smith, human resources director at the federation. “Obviously we want our employees to be healthy, but how they achieve that is up to them.”