Shares of Weight Watchers (WW - Get Report) surged in premarket trading on Friday after the company posted a narrower first-quarter loss and boosted its outlook for the rest of the year.

The subscription based diet and health-lifestyle company lost $10.7 million, or 16 cents a share, in the first quarter, compared to a profit of $39.1 million, or 56 cents a share, in the comparable year-earlier period. The results, however, weighed in significantly better than the 26-cent loss analysts polled by FactSet were expecting.

Revenue came in at $363.2 million, down from $408.2 million a year ago.

Watch to see what happened when @Oprah called some very lucky WW members! Visit https://t.co/n20BdcbnF7 to learn more about how they met their weight loss goals. It's #WellnessThatWorks!

*[People following the WW plan can expect to lose 1-2 lbs/week.] pic.twitter.com/G5DAE9EgMR

— WW. Weight Watchers Reimagined. (@ww_us) March 31, 2019

The company in February warned it had weaker-than-expected participant sign-ups at the beginning of the year. However, it reiterated Thursday its full-year fiscal 2019 revenue guidance of approximately $1.4 billion and lifted its earnings guidance to between $1.35 and $1.55 a share.

Analysts polled by FactSet are currently anticipating full-year per-share earnings at the bottom of that range - $1.35 a share.

Shares of Weight Watchers were up more than 15%, or $3.17, at $23.48 in early trading on Friday after ending the day Thursday at $20.31. The stock has plunged more than 80% over the past 12 months from a 52-week high of $105.73.