Weight Watchers shares ride Oprah wave

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. 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.