Can the Internet help with weight loss?

Yes, according to a new University of Pennsylvania study, but the results may disappoint those looking for a huge drop in pounds, unless they are willing to put forth extra effort.

Intrigued by the popularity of eDiets.com -- an online weight loss program that says it has 233,000 paid users -- the Penn researchers randomly assigned 47 overweight but otherwise healthy women in their early forties to a year's worth of either eDiets.com or a do-it-yourself, book-based weight loss program.

"We thought [eDiets.com] would be great in helping people lose weight," said Leslie Womble, lead author of the study, which appears in the June issue of Obesity Research. "It's so accessible. You can log on at any time, and for some people a barrier to weight loss is time and having to come to group meetings."

Before the study began, all the women met briefly with Womble, a clinical psychologist, who urged them to follow their program as closely as possible. The eDiets participants received a membership (valued at $3 per week) paid for by the researchers, whose funding came from the North American Association for the Study of Obesity and from a federal grant.

Those in the behavioral group each received a copy of "The LEARN Program for Weight Management," a $21.95 self-help manual published in 2000 by psychologist Kelly Brownell, director of the Yale Center for Eating and Weight Disorders.

During the study there were four check-ins, where participants shared eating and exercise records, but the rest of the time they were mostly left to their own devices. All participants were also weighed and measured regularly.

The eDiet participants lost 1.5 pounds at 16 weeks, compared with 6.6 pounds for the behavioral group, the study found. At one year, eDiet participants had lost an average of 1.8 pounds, compared with 7.3 pounds for the behavioral group.

"We were surprised," said Thomas Wadden, director of Penn's Weight and Eating Disorder Program and a co-author of the study. "The findings are intriguing because they're not as successful as findings" from a recent Brown University study of Internet dieters. That study, published last year in the Journal of the American Medical Association, found that adding a regular e-mail counseling message to an Internet weight loss program improved weight-loss results in a group of 92 overweight adults compared with a non-e-mail group using the same Web program.

Susan Burke, vice president of nutrition services for eDiets.com, said that "this was a pretty small study. . . . I can't talk to the numbers that [Wadden] came up with, but we know that the people on the [Brown] study did much better than that. They achieved much more weight loss than the people examined in this study did. I'm not really sure why. We do know that the people we are examining who are utilizing the [eDiets] program are doing very well."

Both the Penn researchers and eDiets representatives note that the online program offers far more variety than it did when the study began nearly two years ago. "This doesn't say how much eDiets.com has changed," Burke said. "I've been here five years and we started with one meal plan. We have 19 options now. We have tons of support, and experts and information and the ability for members to get involved."

Whether you decide to achieve a healthy weight using a Web-based program or another approach, here's what both the Penn researchers and Burke said are some take-home lessons from the study:

Track what you eat. Studies show that people underestimate their food intake by 40 percent. Recording food, time of meals and portion sizes all help to control intake. "Our participants didn't make much use of [the eDiets site], and they didn't lose weight," Womble said. Adds Wadden: "There's a very robust finding that the more participants kept food records, the better they did."

Find ways to be accountable. Research suggests that regularly checking in with someone about your progress significantly boosts the chance of success. If you do decide to join eDiets or another online program, Womble said, "make sure that you log on and participate in meetings and make use of their other resources." These programs have the advantage of being available 24 hours a day, seven days a week, but the study participants logged in only about once per week and so missed the opportunity for additional help and support.

"The more a member logs in, weighs in, checks in and journals, the better they will do," said eDiet's Burke. "Our internal research shows that."

Calories count. Both groups of participants were urged to aim for about 1,200 to 1,400 calories per day -- considered a safe level of intake for gradual weight loss for most overweight women. The eDieters had a tough time staying within that range, as evidenced by their limited weight loss. Food records seemed to indicate that the LEARN program members adhered better to the calorie levels. Not surprisingly, those in both groups who stayed closest to the recommended daily levels saw the best results.

Plan ahead. Knowing what you're going to eat a meal or two in advance seems to help reduce the impulse to eat whatever happens to be in sight. "That's why planning is so great," Womble said. "On the weekend, think about the week ahead. Go grocery shopping. Prepare some food [for the week.]"

Find the healthy foods you love. In the LEARN program, participants are told "you can eat what you want, but it encourages you to eat in moderation, so you do have more choice," Womble said. By comparison, eDiets provides suggested food lists, menus and grocery lists for participants to take the guesswork out of weight loss. "With eDiets, they say this is what you are going to do today."

Stay the course. Both groups improved their eating habits and reported feeling less hungry as the study progressed. By the end of the year, both groups also reported significantly fewer symptoms of depression, the study found. "Whatever modest changes they made for 16 weeks, they were able to maintain them," Wadden said.

Adds Womble: "To a person trying to lose weight, this may not be seen as positive, because one pound is not that much. However, if you talk about realistic weight loss expectations and if you didn't do anything, you could have potentially gained 10 pounds during the year."

Share Your Tips or ask questions about healthy nutrition and activity when Sally Squires hosts the Lean Plate Club online chat, from 1 to 2 p.m. today, on www.washingtonpost.com.

New To The Club? The Lean Plate Club is devoted to healthy eating and boosting activity. To learn more, and subscribe to our free e-newsletter, visit www.washingtonpost.com/leanplateclub.