More and more employers are demanding that workers who smoke, are overweight or have high cholesterol shoulder a greater share of their health care costs, a shift toward penalizing employees with unhealthy lifestyles rather than rewarding good habits. Policies that impose financial penalties on employees have doubled in the last two years to 19% of 248 major American employers recently surveyed. Next year, Towers Watson, the benefits consultant that conducted the survey, said the practice ? among employers with at least 1,000 workers ? was expected to double again. In addition, another survey released on Wednesday by Mercer, which advises companies, showed that about a third of employers with 500 or more workers were trying to coax them into wellness programs by offering financial incentives, like discounts on their insurance.