Jennifer Hudson
Actress and singer Jennifer Hudson is a spokeswoman for Weight Watchers, which, off strong online business, posted increased third-quarter revenues. Reuters

Weight Watchers International, Inc. saw its third-quarter revenue jump 29.6 percent from the prior-year period and net income nearly double, as its online business surged.

The company announced its third-quarter earnings report Tuesday after trading completed.

Revenues totaled $428.4 million, the company said in a release, up almost 30 percent from the third quarter in 2010. Net income rose from $44.4 million to $80.7 million, up 81.5 percent.

We are very pleased to deliver another quarter of strong financial results, David Kirchhoff, president and CEO of Weight Watchers, said in a release.

It is gratifying to see how our continuing investments are driving high levels of consumer interest in our brand and unique approach to weight management.

The two biggest jumps came in the areas of North American meeting revenues and the company's Internet business on its Web site,

North American meeting revenues grew 24.6 percent from last year's third quarter, up to $195.5 million. brought in revenue of $101.9 million, a staggering 68.5 percent increase from the prior year. The Web site had 1,719 active subscribers at the end of the quarter, compared with 1,051 at the end of the third quarter last year.

Weight Watchers readjusted its full-year earnings view to $4.05 to $4.10 per share, compared with a previous expectation of $3.85 to $4.05 per share.

Weight Watchers' gains came on the same day a study from Birmingham University in the United Kingdom found that commercial weight-loss programs like Weight Watchers are more effective and cheaper than programs led by physicians.

The study's participants, 740 overweight or obese adults, were enrolled in Weight Watchers, two other commercial weight-loss programs, or three programs within the National Health Service. The participants generally lost more weight in commercial programs than in NHS-sponsored programs.

Weight Watchers assigns points to various foods and beverages as its weight-loss program.