Weight Watchers shares ride Oprah wave

A sign for Weight Watchers is displayed at office in lower Manhattan, New York October 19, 2015. REUTERS/Brendan McDermid

(Reuters) - Shares of Weight Watchers International Inc WTW.N rose nearly 16 percent on Thursday after the weight management company rode the Oprah Winfrey wave to post its first growth in North American subscribers in at least two years.

Shares of the company were up 3.4 percent at $12.92 in afternoon trading but were still up more than 85 percent since Winfrey added her celebrity appeal to the diet brand by buying a 10 percent stake in October.

More than 4 million shares changed hands by 12:30 p.m. ET, 2.5 times their 30-day moving average.

Subscriber number rose 11.2 pct in North America in the first quarter, the first growth since the company started breaking out the figures in 2014.

The company also forecast its first quarterly and annual revenue growth since 2012.

“The swing to positive revenue growth for the first time since 2012 is greatly amplified by the high-margin, high-leverage nature of the company’s financials, ” Craig Hallum analysts Alex Fuhrman wrote in a note.

Fuhrman also said he expects “total active members to be up in the mid- to high-single digits at the end of 2016.”

Reporting by Subrat Patnaik and Sruthi Ramakrishnan in Bengaluru; Editing by Don Sebastian