"Logging on to Twitter could help you shed a few pounds," the Daily Mail has reported. Its story is based on a study exploring the role of the online social network Twitter as part of a weight loss programme for obese and overweight people.
It found that at six months the number of posts to Twitter was significantly associated with weight loss, with about 0.5% weight loss for every 10 posts to Twitter.
Despite the enthusiastic reporting, this was a small sub-analysis of a larger randomised trial. There was also no randomisation in the study's design, so its findings should be viewed with caution. This is important to note, as the original study found no difference in weight loss between people who had access to Twitter and those who did not.
The sub-group analysis only found a difference in Twitter users: participants who tweeted the most were more likely to lose weight than those who read messages on Twitter but rarely, or never, tweeted themselves ("lurkers", in internet speak).
In this context, the results appear less impressive than reported. But the study does highlight the potential for social media to help provide support for people who want to lose weight.
There is a good deal of evidence that slimming clubs can help people achieve sustained weight loss by promoting supportive social environments. The potential for social networks to act as a kind of virtual slimming club is worthy of exploration.
If the programme was refined further, it could play a role in helping people to lose weight, but further research is first needed in this area.
The study was carried out by researchers from the University of South Carolina and the University of North Carolina. There is no information about any external funding.
It was published in the peer-reviewed medical journal, Translational Behavioral Medicine.
The Daily Mail significantly overstated the study's results. The paper's claim that "Twitter can speed up the rate at which we shed the pounds" is not supported by this study.
The research was a sub-analysis of one arm of a randomised controlled trial of overweight adults. Its aim was to look at weight loss, Twitter use and the type of social support tweeting provides.
The authors point out that although previous research has suggested that social support can be beneficial in a weight loss programme, little is known about whether online social networking can help enhance weight loss.
For the initial study, researchers recruited 96 overweight and obese men and women between the ages of 18 and 60 for a six-month randomised weight loss trial. All participants had to own one of four types of internet-enabled mobile devices – iPhone, iPod Touch, Blackberry or an Android-OS-based phone. They all received a $20 incentive payment for completion of an assessment at three months and a further $20 for completion of the study at six months.
Participants were randomised to one of two groups. The first group received regular podcasts encouraging them to achieve weight loss. The second group received the podcasts as well, but were also told to download two apps to their mobile devices: a diet and physical activity monitoring app and a Twitter app.
They were told to log on to Twitter daily to read and post messages, either by using their existing Twitter account or creating a new one, in order to receive content delivered by a weight loss counsellor and fellow participants. The counsellor posted two messages a day to Twitter in order to reinforce messages from the podcasts and to stimulate discussion.
The participants were weighed at baseline, three months and six months. The two groups completed a weekly questionnaire assessing the number of podcasts they had listened to, and the second group were also asked about their Twitter use.
Each week, posts to Twitter were saved for analysis and the number of posts by participants were calculated. Participants also reported if they posted to Twitter, only read other posts, or did both or neither.
The current study only looked at the group who had access to Twitter via their mobiles. Based on both participants' questionnaires and the researchers' analysis, they were categorised as active users ("active"), users who did not regularly post but read the posts ("readers") and those who did neither ("neither").
The researchers also looked at the content of the Twitter posts and categorised the type of social support the posts provided. These were:
In their analysis for the present study, the researchers examined three factors:
They adjusted their results for several factors, including age, ethnicity and gender.
In the main trial of 96 adults, there was no difference in weight loss between the two groups at either three or six months.
In the sub-analysis of the 47 adults (average age 43 years, BMI 32.9) in the group who had access to Twitter, researchers found there was a total of 2,630 posts to Twitter over the six-month study, with a range of 0-385 total posts per participant. The researchers found that:
The researchers point out that actively using Twitter was associated with greater weight loss, and that participants mainly used Twitter to provide "informational support", largely in the form of status updates.
They argue that further studies are needed to find engaging and useful ways of providing social support for participants in remotely-delivered weight loss programmes.
This useful study looks in detail at the use of Twitter by participants in a weight loss programme, and the qualitative aspects of the social support that can be offered by tweeting. However, as the authors point out, the study did have limitations:
Social networking sites could play a useful role in supporting people who need to lose weight. However, it is noteworthy that in this study most participants stopped using Twitter after three months.
But because of the massive growth in the use of social networking sites in the past decade, any potential effect in reducing obesity levels could bring important public health benefits. Further research into this area would therefore be useful.