(FORTUNE Magazine) – Smokers, doughnut eaters, and bungee jumpers, take heed: You may soon have to pay more than your co-workers for health insurance. An increasing number of companies are tailoring their coverage to the health choices made by individual employees. The game board above illustrates some real-life examples: the obese are penalized at Hershey Foods, and smokers at Baker Hughes, a Texas oil equipment maker, while exercisers collect gifts at Owens-Corning. LSG/Sky Chefs, an in- flight caterer, promotes traffic safety, and Dominion Resources, the Virginia utility, rewards healthy checkups for both employee and spouse. Some companies focus on carrots, offering employees an annual screening, with precise targets for blood pressure, say, and cholesterol levels. Those who pass get a discount on their health premiums; those who don't, pay the standard rates. Hershey Foods breaks out the sticks, with specific penalties for each of five "risk factors," including weight -- an irony, given the company's products! Those who fall short in all five pay over $1,000 more per year than their fitter colleagues. Other employers crack the whip at claims-paying time. Ralston Purina's optional Well-Med plan, for example, requires a greater co-payment for medical claims that result from smoking, alcohol abuse, or driving without a seat belt. Though the new health plans may seem discriminatory, they haven't yet sparked any major lawsuits. On the contrary, says Camille Haltom, of benefits consultants Hewitt Associates, "some of the toughest programs we've seen were actually designed by employee groups, or with union involvement." But other experts think employers are on an awfully slippery slope. Paul Terry, of the Park Nicollet Medical Foundation in Minneapolis, wonders, "Why aren't we going after the horseback riders, world travelers, and people with pools in their backyards? They're also taking risks that the rest of us have to pay for."Some companies are, in fact, ahead on that. Pennsylvania's Latrobe Steel, a Timken subsidiary, has increased the co-payments for anyone who gets hurt drag racing, sky diving, or bungee jumping.