Researchers at the Northwestern University show that online dieters with high social embeddedness - who logged in regularly, recorded their weigh-ins and 'friended' other members - lost more than 8 per cent of their body weight in six months.
The less users interacted in the community, the less weight they lost, the study found.
"Our findings suggest that people can do very well at losing weight with minimal professional help when they become centrally connected to others on the same weight loss journey," said Bonnie Spring, professor in preventive medicine at Northwestern University Feinberg School of Medicine.
Scientists found that users who did not connect with others lost about 5 per cent of their body weight over six months, those with a few friends (two to nine) lost almost 7 per cent and those with more than ten friends lost more than 8 per cent.
More From This Section
"There is an almost Facebook-like social network system in this programme where people can friend each other and build cliques," said Luis A Nunes Amaral, senior author of the study.
Spring had access to a large dataset from CalorieKing.Com's online weight-loss community.
Amaral's lab had the expertise to analyse user data and uncover trends in this complex network.
Engagement, such as recorded weigh-ins, friendship requests and online communication, was analysed. The scientists did not have access to any of the text that was exchanged between users.
"We found that the frequency with which you report your weight is a good indicator of positive outcomes," Amaral said.
"If you monitor your weight, you are engaged. If you communicate online with other people you are even more engaged, and when you need support you might be able to get it. There are some nice characteristics about this social network," Amaral added.