The Obama administration issued final regulations Wednesday designed to prevent companies from discriminating against sick employees through corporate wellness programs.

The programs, which have gained in popularity in recent years, provide incentives for employees to improve their health. Some give medical insurance discounts to workers who meet specific metrics for blood pressure and body-mass index.

But patient advocate groups have complained that such programs could allow companies to penalize workers who have illnesses such as diabetes or heart disease.

The rules issued Wednesday require companies to provide “reasonable alternatives” to employees who cannot meet health benchmarks but still want the discounts. They also allow for workers to involve their physicians to help tailor programs with their employers.

“These rules will help ensure that wellness programs are designed to actually promote wellness, and that they are not just used as a back-door way to shift health-care costs to those struggling with health problems,” Ron Pollack, executive director of Families USA, a health advocacy group, said in a statement.

Some business groups, however, expressed concerns about the rules. Companies are increasingly relying on the programs to encourage workers to adopt healthier lifestyles and to reduce their medical costs. Helen Darling, executive director of the National Business Group on Health, said the rules could be a deterrent for companies.

“We think this is pretty restrictive because it adds a burden they don’t really need,” she said.

Business groups have advocated for wide latitude to administer wellness programs and gained greater flexibility to do so under President Obama’s health-care law.

A report released Wednesday that was prepared for the departments of Health and Human Services and Labor by Rand Corp. found that about half of large employers offer some sort of wellness program, although very few offer the kind in which financial rewards are provided to people who pass physical tests.

The study found that the programs appear to improve many aspects of workers’ health and may reduce companies’ health-care costs.