Oprah Winfrey turned her weight-loss journey into a business. Here's how her health empire has evolved.

Oprah Winfrey turned her weight-loss journey into a business. Here's how her health empire has evolved.

"The Oprah Effect" sent WeightWatchers' stock soaring (and tumbling).Matt Winkelmeyer/Getty ImagesOprah Winfrey is promoting her new book, "Enough," which she cowrote with Dr. Ania Jastreboff.The book is the latest step in Winfrey's long journey with the business of weight loss.Since the '90s, Winfrey has been combining her personal health and fitness with business.Oprah Winfrey has spent years turning her private health journey into a public co…