CHICAGO (CBS) — Shares of Weight Watchers were soaring Monday, thanks to the heft of former Chicago talk show queen Oprah Winfrey.

For decades, Winfrey has publicly shared her struggle with weight control. In 1998, she scored her highest ratings ever with a show that dealt with her dramatic weight loss.

Now, Weight Watchers International has announced a major deal with Winfrey, who is buying a 10 percent stake in the company for more than $43 million. She also will join the board of directors and make personal appearances for the company.

Meantime, the company has signed a five-year deal giving it the right to use Winfrey’s name and image in promoting its products and services.

The company’s stock soared on news of the partnership.