Being in a team can increase your chance of losing weight
By Liz Lockhart
Could weight loss be contagious? A new study has shown that teammates in a weight-loss competition significantly influenced each other’s 
loss of weight.
The study was conducted by researchers from the Miriam Hospital’s Weight Control and Diabetes Research Centre and The Warren Alpert Medical School of Brown University. They found that team members achieved similar weight loss results. The participants who reported that their teammates played a significant role in their losing weight actually lost the most weight.
‘We know that obesity can be socially contagious, but now we know that social networks play a significant role in weight loss as well, particularly team-based weight loss competitions,’ said Tricia Leahey, Ph.D., of The Miriam Hospital and Alpert Medical School. Leahey is the lead author of the study.
She added ‘In our study, weight loss clearly clustered within teams, which suggested that teammates influenced each other, perhaps by providing accountability, setting expectations of weight loss, and providing encouragement and support.’ Leahey noted that online team-based weight loss interventions are increasing in popularity as a way to encourage weight loss.
The study looked at the effects of teammates and social influence on individual weight loss during a weight loss competition. The competition which was studied was the 2009 Shape-Up Rhode Island campaign which is a 12-week online weight loss challenge.
Study participants joined with a team and competed against other teams in three divisions – weight loss, physical activity and pedometer steps. 3,330 overweight or obese individuals took part in the competition. They were divided into 987 teams averaging between five and 11 members each.
The researchers noted that weight loss outcomes were determined by which team an individual was in. Participants who lost at least 5% of their initial body weight were considered to have lost significant amounts of weight. They tended to be on the same teams and on a team with more teammates in their weight loss division.
Leahey said that individuals who reported higher levels of teammate social influence increased their odds of achieving a significant weight loss by 20%. This effect was more significant than any other team characteristic.
‘This is the first study to show that in these team-based campaigns, who’s on your team really matters. Being surrounded by others with similar health goals all working to achieve the same thing may have really helped people with their weight loss efforts,’ Leahey said.
It was also noted that team captains lost more weight than team members, which may be due to their increased motivation and engagement in the campaign. Because of this, Leahey says, future weight loss competitions may consider requiring team members to share the leadership role.
‘We’re all influenced by the people around us, so if we can harness this positive peer pressure and these positive social influences, we can create a social environment to help encourage additional weight loss,’ she concluded.
Source: The Miriam Hospital
