Photo illustration by Viktor Koen for Newsweek

Jeanne Dulaney is a time-crunched software consultant who often eats out on the company expense account. But the 51-year-old from Montgomery, Ala., paid the price for her frequent restaurant dining: 40 extra pounds on her 5-foot 5-inch frame. With little time to commit to a real-world weight-loss program, Dulaney became a mouse-clicking dieting maven after seeing an ad for ediets.com. “I’m on my computer all the time, so I figured I’d give it a try,” she says.

Three years later, Dulaney is nearly 50 pounds lighter. She’s even started to run half-marathons with some new- found friends, other members of ediets.com. “Everyone who is trying to lose weight needs help,” she says. “I got mine from my computer.”

No one actually knows how many people like Dulaney have found weight-loss success with Internet-based commercial programs. But what is clear is that Web-based diets are becoming a booming part of the $30 billion U.S. weight-loss industry. The choices are endless. Internet-only weight-loss programs like ediets.com, diet.com and WebMD, and diet icons like Weight Watchers and South Beach are all competing for your weight-loss bucks. Even fitness franchise Curves opened a new online dieting site last week.

Although research into the effectiveness of online dieting is in its infancy, science is showing that it probably won’t hurt you. And, depending on the program’s components, these online purveyors may help you drop some pounds. With 24/7 access and anonymity, the sites may be helpful for folks who are too busy, or too shy, to attend a more structured program.

In a study published in The Journal of the American Medical Association, Brown University researchers found that Internet dieters who received weekly e-mail advice from behavioral therapists and had peer support through bulletin boards lost three times as much weight in six months as those who received only Internet-based diet and exercise information.

“There are a lot of unanswered questions about how the Internet can help people lose weight,” says Rena Wing of the Warren Alpert Medical School of Brown University and a cofounder of the National Weight Control Registry. “But what’s clear is, there needs to be some type of professional guidance available.” Look for programs that allow you to interact with a dietitian or other weight professional who can help individualize a program. Wing also recommends looking for sites that incorporate proven real-world strategies like nutrition guidance, physical activity and a tracking system that allows you to log meals and exercise.

The good news is that many online programs do offer a combo platter of personalized service, with most costing about $5 a week. At diet.com, you can get a customized diet-and-exercise program based on your personality type. If you’re too busy to cook, ediets.com will send you fresh, chef-prepared meals five ($99) or seven ($131.60) days a week. WebMD will give your favorite family recipe a healthy makeover

Check out consumerreports.org or onlinediet-services-review.toptenreviews.com to get an idea of what these programs can do for you and your waistline. In Dulaney’s case, she lost weight and gained some new best friends.

With Roxana Popescu