This month, more than half of Americans probably made health-related New Year’s resolutions, judging from past data, but few are likely to stick to them. Employees at CFI Westgate Resorts, an Orlando, Fla.-based vacation properties company, might consider themselves lucky: They have an incentive to get healthy. If they join in the company-wide weight-loss contest this month and succeed in reaching their goals, they could win cash prizes or a luxury vacation. Inspiration for the contest, now in its second year, came from CEO David Siegel, who himself recently lost more than 20 pounds. “He put it on the radar,” says Mark Waltrip, chief operating officer at Westgate, adding that in the contest’s first year, some employees lost up to 60 pounds. Employers like Westgate are trying to push employees into healthy lifestyles, including reducing obesity, a condition estimated to cost U.S companies $13 billion per year, according to the Washington D.C.-based National Business Group on Health.…