GREEN BAY, Wis. — Truck drivers — the people who deliver our food, cars and clothing — have one of the most dangerous jobs in America — accounting for nearly 15 percent of U.S. work-related deaths. And that's only counting the accidents.

They are also more at risk than average Americans for a number of health problems. Obesity is rampant. Many don't bother to wear seat belts because their stomachs get in the way. About one in four have sleep apnea. Half of them smoke.

The latest research in an upcoming report drives home those points and may help influence government regulations for truck drivers' health, which are under review. The Federal Motor Carrier Safety Administration is considering tightening its rules for conditions including diabetes and high blood pressure. And many companies are stepping up their own efforts at improving health.

"It takes a while to undo years and years and years of unhealthy behavior," said Christie Cullinan of the American Trucking Associations, which represents about 2,000 companies and suppliers. "But I think companies are having to look at this because of the skyrocketing health-care costs and related workers compensation costs."

Drivers are tested every two years to maintain their licenses, which are issued by states. Waivers can be granted, but generally commercial drivers can't be licensed if they have severe high blood pressure or severe heart conditions. Other aspects of drivers' health, like weight and smoking, aren't regulated.

"They can't say, 'You can't be obese' and they can't force you to stop smoking," said Gerald P. Krueger, a psychologist who compiled the latest research by the Transportation Research Board. "The government shouldn't regulate that. But we've been trying to educate people to the linkage between being a healthy person and a safe driver."

Krueger said trucking companies need to do more to foster better health among their employees, whether it's to reduce health-care costs or hang onto employees in an industry where turnover is high and shortages growing.

It's not clear how many companies are making efforts. The trucking associations group says it is planning a survey. The group estimates there are 1.3 million long-haul drivers nationwide.

An Associated Press spot check of companies revealed these initiatives:

• Celadon Group Inc. has stationed nurses at its main facility in Indianapolis and encourages its 3,200 drivers in the United States and Canada to get blood pressure and cholesterol checks. Doctors are on call if needed, and Celadon pays all expenses. The company says it's helped trim its $10 million annual health-care bill.

• Melton Truck Lines Inc. replaced sodas in the Tulsa, Okla., headquarters vending machines with green tea, water and diet drinks. The company also offered a 12-week weight-loss series.