WASHINGTON (Reuters) – More than half of large U.S. employers offer wellness programs like gym memberships and weight loss assistance to their workers, and say these help reduce medical costs, according to a survey released on Tuesday.

The MetLife survey found that 70 percent of employers who offer wellness programs saw them as a “very important tool for employee retention.”

The 2007 survey of 1,380 full-time employees and 1,652 managers at companies with a minimum of two employees represents a mix of industries and geographic regions, MetLife said.

It found that 57 percent of employers with 500 or more workers provide some sort of wellness program such as smoking cessation, weight management, an exercise plan or cancer screening.

Only 16 percent of smaller employers do, the survey found.

And about four out of five employers with wellness programs add incentives, with 40 percent offering gym memberships, 36 percent awarding gifts or prizes and 27 of employers offering a discounted employee contribution to medical plans.

Only nine percent of employers impose financial penalties on employees who do not meet wellness guidelines, a percentage that has remained steady for two years, the survey found.

“Health insurance is expensive, but employees surveyed for the MetLife study indicated that medical coverage is the second most important factor affecting their loyalty to their employer after salary/wages,” said Dr. Ronald Leopold, a vice president at MetLife Institutional Business.

“Since medical coverage has essentially become ‘table stakes’ for competitive employers, a way to keep health insurance viable and offset future spending for chronic medical conditions can be to invest in targeted wellness and prevention programs,” he added in a statement.

(Reporting by Maggie Fox; Editing by Julie Steenhuysen)