Want to stay trim? Well, then do away with your fat pals, suggests study with mounting evidence.
A new American research has found a strong link between teenagers' own weight and that of their closest peers, reports The BBC.
The journal Economics and Human Biology further justifies the notion of imitative obesity - aping of friends who gain weight.
When they looked at weight changes over time, they found having a fat friend could lead to weight gain for a child.
The study authors from the University of Hawaii say they cannot tell from their work whether overweight teens influence their friends to become overweight or whether obese adolescents simply choose to flock together.
A spokeswoman from Weight Concern said: "We do learn from our peers and eat with our friends, so these children may be picking up unhealthy habits.
"But I would not assume that the overweight teenagers are necessarily the ones with the bad habits. Most teenagers have unhealthy diets, but not all of them are obese.
"And most of the food consumed is still at home with the family."