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Shares of Weight Watchers International Inc.  (WTW) fell 8.3% to $32.16 Friday after JPMorgan analyst Christina Brathwaite downgrades the weight management services company to neutral from overweight with a price target of $37.

Brathwaite said in a research note that she was "throwing in the towel" as early channel checks point to a weak 2019 start for the business. She said that she believed traffic to the company's website and engagement on its mobile app are down double-digits year-over-year, which could indicate that new member growth will likely start 2019 at a slower pace than previously anticipated.

Braithwaite said Weight Watchers had announced at the beginning of 2017 a long-term target of achieving more than $2 billion in revenue by the end of 2020.

"While it's still very early in the New Year Resolution season and (Weight Watchers) could make up for the shortfall in the coming months (particularly as some of the shortfall may be related to the government shutdown as furloughed workers are less likely to start a diet membership)," Braithwaite wrote, "we believe current trends will make it difficult for the company to generate significant growth in members, with our checks indicating new weight loss brand Noom may be siphoning traffic from (Weight Watchers)."

Noom is a new mobile app weight loss program, Braithwaite said, which includes enhanced personalization by assigning each member a "health coach" who answers questions, provides tips, and helps keep members on track towards goals.

In November, Weight Watchers, which recently changed its name to WW, posted third-quarter net income of $70.1 million, or $1 per share, up from $44.7 million, or 65 cents, a year ago. Revenue totaled $366 million, up 14% from a year ago, but missed analysts' expectations of $379 million.

The company said it ended the third quarter with 4.2 million subscribers-- up 25% year over year, but that number fell from 4.6 million subscribers in the first quarter and 4.5 million in the second quarter.

At that time, CFO Nicholas Hotchkin said during a conference call with analysts that, historically, about 40% of the company's annual member recruitments have occurred during the first quarter. Therefore, Hotchkin said, "each year first quarter is our peak for end of period subscribers and each year end is our low point."