Is slimming contagious?

Want to lose weight? Then befriending slimmers will help you shed the pounds, say scientists.

A study found that overweight participants lost the most weight when they were supported by those with similar health targets.

Researchers now believe that, just as obesity has been found to be contagious, weight loss can also have a ripple effect.

Lead researcher Tricia Leahey, Ph.D., from the Miriam Hospital, Brown University said: “We know that obesity can be socially contagious, but now we know that social networks play a significant role in weight loss as well. In our study, weight loss clearly clustered within teams, which suggests that teammates influenced each other, perhaps by providing accountability, setting expectations of weight loss, and providing encouragement and support.”

Prof Leahey investigated the results of the 2009 Shape Up Rhode Island (SURI) campaign - a 12- week online weight loss competition. During the dieting contest, participants joined a team and competed against other groups. In total 3,330 overweight or obese individuals (BMI of 31.2 or more) were involved, representing 987 teams, each averaging between 5 and 11 members.

Participants who lost the most weight (at least 5 percent of their initial body weight) tended to be on the same teams. And those who reported higher levels of teammate interaction increased their odds of achieving set targets by 20 per cent.

The current study, published in the journal Obesity, is the first to examine the effects of teammates and social influence on individual weight loss.

Prof Leahey added: “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.”

Obesity can spark numerous health problems, including high blood pressure, heart disease and diabetes.