Weight Watchers International shares are rapidly gaining weight.
The stock is on a tear after the company raised its full-year earnings outlook, calling a push within its massive subscriber base to round out fiscal 2017.
"We are excited about the upcoming winter season," Chief Executive Mindy Grossman said in a statement. "We are confident our business momentum will continue throughout the balance of the year."
Weight Watchers shares were climbing more than 15 percent Tuesday morning on the news. Its shares have risen more than 360 percent in 2017.
On Monday evening, Weight Watchers reported net income of $44.7 million, or 67 cents a share, for its fiscal third quarter, up from $34.7 million, or 53 cents per share, one year earlier.
Analysts were calling for earnings of 51 cents a share, according to a survey by Thomson Reuters.
Weight Watchers' quarterly revenue climbed 15 percent, to $323.7 million, up from $280.8 million last year. Analysts were calling for sales of $316 million, Thomson Reuters said.
Not expecting to slow down anytime soon, Weight Watchers has raised its earnings outlook for the full year, now expecting to earn $1.77 to $1.83 a share versus a prior forecast of $1.57 to $1.67.
The weight-loss company ended the latest quarter with 3.4 million subscribers, up 18 percent from last year.
Weight Watchers owes some of its success to Oprah Winfrey, who acquired a stake in the business about two years ago and became the face of its campaigns. Since then, Weight Watchers has posted eight-consecutive quarters of membership increases.