Wired of Friday Carol PowerAnyone who has ever been to a Weight Watchers meeting knows how tedious it can be to stand in line waiting for your turn to be weighed. And when standing on the scales, there can be the embarrassment of turning out to being heavier than you think you are.

After the weigh-in, Weight Watchers offers motivational sessions where a team leader urges all the participants to eat the right foods and stick to the daily points system.

This kind of weekly support group is a voluntary option and can either encourage someone to lose weight or put them off. Whatever your view, there are now options available for dieting online, from the privacy of your own home and being accountable only to yourself.

For a 40-year-old company such as Weight Watchers International, it was an obvious move to license its name and products to an independent, privately held company such as WeightWatchers.com.

Established in 1999, WeightWatchers.com has grown from $46 million (€38.9 million) in revenues in 2002 to $80 million in 2003 - double that of its nearest competitor, eDiets.

Both companies have seen more and more dieters signing up for their online services in the past few years.

"We give our members the ammunition to succeed with a customised diet plan," said Ms Susan Burke, vice-president of nutrition services at eDiets.

Its average customer is a female aged in her late 20s or early 30s and she generally weighs about 20 pounds higher than her healthy weight.

Surveys have revealed that approximately half of all Americans are attempting to lose weight at any given time and about two-thirds of American adults are overweight or obese.

Net annual profits in the United States' dieting industry have now reached $35 billion.

Internet dieting is taking off because it attracts people who either don't have the time or the inclination to attend face-to-face meetings, or who are too embarrassed to get on a scales in front of strangers.

About three million people have tried different online weight-loss plans in the four years in which diets have been offered over the internet. About 750,000 people currently use online weight-loss plans and, according to Nielsen NetRatings, 10 million people log on to weight-loss sites every month.

But can the internet be just as effective in helping someone lose weight as attending a meeting in person?

In February, researchers at the University of Vermont suggested that the internet appears to work as well as offline programmes in maintaining long-term weight loss. They published their research in the journal Obesity Research.

The Vermont researchers tracked 255 healthy overweight and obese adults during a six-month behavioural weight control programme conducted over interactive television. Treatment was followed by a 12-month weight maintenance programme with three conditions: frequent in-person support, minimal in-person support and internet support.

The results showed there were no significant differences among the groups in weight loss over the 18 months.

Participants assigned to an internet-based weight-maintenance programme sustained comparable weight loss compared with individuals who continued to meet face-to-face. Therefore, they concluded, the internet appears to be a viable medium for promoting long-term weight maintenance.

But it seems that having some kind of community support on the internet does helps.

According to a 2001 study from Brown University, dieters who received weekly advice from behavioural therapists on the internet lost three times as much weight in six months - nine pounds instead of three pounds - as those who just had access to information about diet and exercise on the internet.

Participants who received online advice from behaviour therapists logged on twice as many times during the first three months as those who just had access to information online.

Among the online dieting sites, eDiets has 200,000 current members who can log on to 100 different support boards and sign up for one of 17 diet plans. Since 1996, 1.3 million members of eDiets have lost a combined 4.5 million pounds.

There is no registration fee and the price for a weekly meal plan is $2.99 with $1.00 extra a week for a fitness plan. It offers expert eating disorder specialists, chat rooms, more than 50 online meetings a week and live support around the clock from a call centre in Deerfield Beach, Florida.

"The beauty of online programmes is that members can get support 24 hours a day," according to Ms Burke of eDiets.

"We're trying to make people understand it's not just about diet but lifestyle."

She stressed that the anonymity and convenience of the internet is enhanced by the economic factor.

"We're a fraction of the cost of other diet programmes and our members can use us as little or as much as they like," she said.

EDiets' most well-known competitor would probably be Weight Watchers International.

Ms Grace Ann Arnold, a spokeswoman for WeightWatchers.com in New York, said that it offers two subscription products: eTools for existing Weight Watchers meetings' members, which costs $29.95 for a three-month pre-paid subscription or $12.95 a month; and Weight Watchers Online, which is designed for independent dieters and costs $59.95 for a three-month pre-paid subscription or $14.95 a month.

"More people are trying to diet on the internet because they can get health and nutrition information and recipes of the day," Ms Arnold said.

"Most people stay on our site for 30 minutes, which is the highest in the Nielsen NetRatings health, fitness and nutrition category and nearly double our nearest competitor."