Candy-bar maker Mars Inc. thinks cocoa is good for you.

Yesterday, the McLean-based maker of Snickers and M&Ms named Catherine E. Woteki, a former undersecretary of food safety in the U.S. Department of Agriculture, as its global director of scientific affairs as part of an effort to get "more serious" about health and nutrition.

Woteki, who is dean of the College of Agriculture at Iowa State University, said Mars, which also makes such products as Uncle Ben's rice and pet food, is more than just a candy company. And besides, she said, everyone needs the occasional treat. "The key is always moderation and a healthy lifestyle," she said in a telephone interview.

Last week, closely held Mars started a new division, Mars Nutrition for Health & Well-Being, that will develop "heart-healthy" foods. Marlene Machut, a spokeswoman, said the division grew out of millions of dollars of research into chocolate-making.

"The idea was to try and optimize flavor and the resulting chocolate we use in our products," Machut said.

Mars's new emphasis on healthful foods follows the path of other food companies, most notably McDonald's, which added salads to its fast-food menu of burgers and fries in an effort to broaden its appeal and change its image.

The new division will take over marketing of a Mars product line already being sold online -- CocoaVia, a granola-based crunch bar full of cocoa flavanols, a naturally occurring compound that is usually stripped from cocoa beans in processing to make chocolate. Machut said CocoaVia came out of 15 years of research in which Mars scientists concluded that flavanol had molecular similarities to antioxidants in green tea and red wine.

Machut said the company is looking into other "alternative channels" to sell CocoaVia.

Mars is owned by the three grandchildren of founder Frank Mars, who have a combined worth of more than $30 billion, Forbes magazine has estimated. The company, which provides few details of its operations, said it had $16 billion in revenue last year.

The CocoaVia crunch bars are selling for an introductory price of 30 bars for $30, and the Web site offers to ship more automatically each month. For the "intended health benefits," the Web site says, "you should consume two portions of CocoaVia snacks every day."

Bonnie Liebman, director of nutrition for the Center for Science in the Public Interest, questioned Mars's claims. "The evidence is not very consistent and still skimpy that flavanols can reduce the risk of heart disease," she said. "I think Mars is going overboard with its claims for flavanols."

Although Mars does not make similar health claims for all of its candy bars, Liebman said consumers may get that message anyway.

"The chocolate industry wants to turn it into a health food, but it's still candy," she said. "With two out of three Americans overweight, the last thing we need is another excuse to eat chocolate."