At the Mariani Nut Co. outside of Sacramento, workers wearing hairnets sort a steady stream of almonds and walnuts as they pour onto conveyor belts. This is a pretty typical scene at a processing plant.

But there’s something surprising underway not far from the factory floor. Middle-aged factory workers are dripping sweat and pumping iron at the plant's on-site gym.

A group of Latina workers show up regularly to CrossFit classes to lift weights, run and jump rope in a converted conference center.

Amelia Damey -- a sanitation worker -- came over to class after a shift of cleaning, mopping and sweeping. Damey, 58, says she'd never been to a gym before. But with this gym on site and free classes she decided to try it out.

"I was not even able to do the jump rope one or two, twice. I just tried to keep jumping but I couldn't,” she says.

Damay says she’s lost and kept off 10 pounds since she started coming to the gym. She also has more money in her pocket. As a reward for her efforts, Mariani Nut Co. now picks up Damey's share of her health insurance premium, which is about $1,100 a year.

Robin Stenson, HR manager for the nut company, says the incentive program came about after employees took a health screening test three years ago.

“We found that the rate of diabetes, obesity and high blood pressure was very alarming," she says. “That kind of was the catalyst for us to try to do something proactive.”

Alarming because almost every worker had one of these conditions. So the company put up a couple of thousand dollars for gym equipment. And now Stenson says it spends about $25,000 a year on its wellness program. While that may seem like a lot, in the world of health care spending, it’s not.

“I’d say that’s a reasonable amount considering that you’re paying over a million dollars in premiums as far as insurance goes,” she says. “That’s just a drop in the bucket.”

Majority of businesses trying to get workers healthier

A growing number of businesses are looking for new ways to save money on their health insurance costs.

Almost 80 percent of companies offer a worksite wellness program, says Don Powell, president and CEO of the American Institute for Preventive Medicine and an adviser to businesses on wellness programs.

He says businesses are finally catching on to the fact that the vast majority of health care spending is on preventable diseases -- many of them linked to obesity. But there's a snag when it comes to lower-wage workers.

"It is more difficult to motivate blue-collar workers to participate in wellness programs because they don't have the same degree of interest of people of higher socioeconomic backgrounds,” Powell says.

But at the same time blue-collar workers are more likely to be overweight, diabetic and use tobacco. So, what's a business to do?

"To do nothing costs them money,” he says. “The average employer is spending around $10,000 per employee per year for health care and that's just not sustainable."

So, more companies are balancing incentives for better health with penalties for those who don't want to make changes. And under President Obama’s health care law, employers will have more flexibility to raise the stakes on each side.

Overweight workers who won't diet or get on an exercise program, for instance, could see their premiums jump by as much as 30 percent. And with permission from the federal government, that amount could reach 50 percent.

More than carrots and sticks

Powell says he's not convinced these types of carrots and sticks make a lasting real difference. To get the best results the workplace culture has to change, he says.

"That consists of the CEOs and management people being involved in the challenges and losing weight along side the people that work in the processing plant," says Powell.

This is happening back at the Mariani Nut Co. Robin Stenson, HR manager, is wearing her CrossFit shirt and spotting an employee lifting weights. She’s hooked on the workouts now and says she comes to most of the classes. And Stenson says they’re adding even more variety to the gym lineup; now they have kickboxing and yoga classes.

This story was produced with the California HealthCare Foundation Center for Health Reporting.