Yoga instructor Niki Peters, far right, of Core Power Yoga, leads employees at Periscope in a shoulder stand during a class over the lunch hour. Periscope, a Minneapolis marketing and advertising agency, held a competition among employees for conditioning and weight loss. Like many employers, the company is trying to keep health care costs down. (John Doman, Pioneer Press)

Think your weight is nobody’s business? Try telling that to employers.

Faced with ever-soaring health insurance costs, more employers are putting wellness programs into overdrive. They’re no longer hinting that it might be time to think about getting healthier. They’re making it part of the culture.

Consider General Mills. The food giant, a regular on lists of best places to work, has long offered fitness programs to its corporate employees in Golden Valley. Now, manufacturing plant managers across the country are using the corporate wellness programs as models for their own customized programs.

The company spells out the importance of good health in a wellness mission statement distributed to employees: “We would like every General Mills employee to have an active lifestyle, a healthy weight, a normal cholesterol level, normal blood pressure and to be a nonsmoker.”

It’s tough for employees to miss the company’s fitness opportunities. Its offerings range from dodgeball and cross country skiing on Fridays to small group meditation sessions for obese employees and classes on meal portion control. Orientation programs hammer home the health imperative in small group meetings.

Do employees have the choice of opting out?

“Of course,” said Tim Crimmins, the company’s vice president of health and safety, who acts as chief medical officer. But, he adds, for those who don’t take part, “It’s a little like not being invited to the party.”

Garry Mathiason, a partner with the employment-law firm Littler Mendelson in San Francisco, said his firm is among those researching how far employers can go without breaking laws protecting medical privacy and access to health care.

“We kept getting questions by the carload from our clients as to what they could do and couldn’t do,” he said.

Many employers offer financial carrots of sorts to workers who participate in certain programs — think discounted gym memberships or bonuses for filling out health assessments. Many want to tie money to measurable results. So, for example, instead of offering $100 for completing an assessment, a worker would have to pare his body mass index to less than 25 to earn the money.

“That’s a really, really slippery slope,” cautioned Jim Winkler, leader of Hewitt’s Health Management Consulting practice.