By Stephanie Stahl

By Stephanie Stahl

PHILADELPHIA (CBS) — Billionaire media mogul Oprah Winfrey and Weight Watchers are teaming up. She has acquired a 10 percent stake in the diet company. Today’s announcement quickly caused the stock price of Weight Watchers to soar.

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Oprah is going on a diet again, and it’s worth a lot of money to her and Weight Watchers. In a statement, Oprah said she believes in Weight Watchers enough to make a big investment because the program has given her the tools she needs to make lasting changes in her struggle with weight. Oprah Winfrey is so convinced Weight Watchers will help her lose weight, that she has invested $43.2 million in the diet company and will become an advisor.

John Birnhak is vice president of Philadelphia Weight Watchers, one of the oldest and largest franchises. He thinks Oprah will bring a much-needed boost to business.

“I think we’re going to be really happy working with her,” Birnhak said.

The key to Weight Watchers’ success is weekly meetings where members support each other and share ideas. Members are allotted an individualized point system that essentially tracks calories. But Weight Watchers sales and profits have been declining with competition from fitness trackers and diet apps. Oprah says she’ll be using the Weight Watchers mobile app and work with a coach.

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We know Oprah has a history of yo-yo dieting, losing and gaining weight. What if she doesn’t lose weight on Weight Watchers?

“An individual’s weight loss journey is private and personal,” Birnhak said. “I’m sure of our program and if you follow the program you’ll be successful and she will.”

The stock price of Weight Watchers doubled with the Oprah announcement. The company also said instead of just focusing on weight loss, it’s shifting focus to overall health and wellness.

Philadelphia Weight Watchers

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Stephanie Stahl