CHICAGO - Where a teenage girl sees herself on her school's social ladder could sway her future weight, a study of more than 4,000 girls finds.

Those who believed they were unpopular gained more weight over a two-year period than girls who viewed themselves as more popular. Researchers said the study showed how a girl's view of her social status has broader health consequences.

The girls in the study were still growing -- their average age was 15 -- and all gained some weight. But those who rated themselves low in popularity were 69 percent more likely than other girls to increase their body mass index by two units. That's the equivalent of gaining about 11 excess pounds, which is more than the typical weight gain for adolescent girls, the researchers said.

Girls who put themselves on a higher rungs of popularity gained some excess weight, but less -- about 6½ pounds.

"How girls feel about themselves should be part of all obesity prevention strategies," said the study's lead author, Adina Lemeshow, who began the study as a graduate student. She now works at the New York City Department of Health and Mental Hygiene.

Weight and height data were self-reported, a weakness in the study that the researchers acknowledged. The research, appearing in January's Archives of Pediatrics & Adolescent Medicine, used data from an ongoing study.

"The reason this paper is so important is it has broader implications beyond weight gain," said Clea McNeely of Johns Hopkins Bloomberg School of Public Health, who was not involved in the research. "Subjective social status is not just an uncomfortable experience you grow out of, but can have important health consequences."

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