Most big employers provide wellness programs now, and the Affordable Care Act gave the idea a boost in 2010 by letting companies offer employees financial incentives— such as lower health insurance premiums, gift cards or prizes—worth up to 30 percent of the cost of their health insurance.

But as the wellness industry has grown, questions have started to arise about just how effective these programs really are—and how fair. It’s not clear the programs financially benefit employers, and evidence is also mixed on whether they make employees healthier. And now, some employees have begun to bristle at the omnipresence of wellness in corporate culture and see the requirement to share personal health data with their employer as an intrusion on their privacy.

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