A few months ago, Tracy Raymond, a first-grade teacher in Palm Beach Gardens, FL, discovered that she was too fat for her school. A 50-year-old mother of two, Ms. Raymond has always carried around extra padding, but it never bothered her. “I know I’m heavier than I should be for my height, but I’m not obese,” she says. “I really don’t care.”

If the diet police has its way, she might have to start caring. Because according to her employer, her weight is a big problem—so much so that she was warned that if she didn’t lose weight and lower her cholesterol, either by participating in a wellness program or fixing the problems on her own, her insurance premiums would increase by $50 a month.