(Reuters) - Weight Watchers International Inc (WTW.N) reported a 21 percent drop in fourth-quarter net revenue, hurt by a drop in subscriptions, sending its shares down 19 percent.
Weight Watchers is battling intense competition from a plethora of options including the no-cost Loose It, mobile app Nike Run and fitness trackers made by Fitbit Inc (FIT.N).
Weight Watchers roped in media mogul Oprah Winfrey as its public face, using her mass appeal to boost subscription numbers in a bid to reverse a nearly three-year decline in sales.
The company said in October Winfrey would make a $43.2 million investment for a 10 percent stake and added her to its board.
Weight Watchers' sales fell to $259.2 million in the fourth quarter ended Jan. 2, from $327.8 million a year earlier.
Active subscriber numbers fell 4.8 percent to 2.39 million.
The company reported a net loss of $11.3 million, or 18 cents per share, compared with net income of $4.4 million, or 8 cents per share, a year earlier.
The quarter included a $13.6 million one-time transaction expense related to the Winfrey partnership, the company said.
Weight Watchers' shares were trading at $12.89 after markets closed on Thursday.
(Corrects active subscriber numbers to "2.39 million" from "2,389.6" in paragraph 6)
(Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Maju Samuel)