Teen girls who frequently weighed themselves were more likely than others to resort to unhealthy dieting measures, and some ended up gaining close to twice as much weight, a study of Minnesota students found.
The most scale-obsessed girls in the University of Minnesota research were more likely to skip meals, use diet pills or laxatives, smoke and binge and vomit to lose weight.
"The act of getting on the scale, weighing yourself every day, can lead to an unhealthy weight preoccupation," said lead researcher Dianne Neumark-Sztainer, a professor at the university's School of Public Health. "And teenage girls who are concerned about their weight are at great risk for unhealthy weight control behaviors."
The study, published in this month's issue of the Journal of Adolescent Health, surveyed 2,516 Minnesota junior high and high school girls and boys in the 1998-99 school year and followed up in 2003-04.
Close to 10 percent of the girls said at the beginning of the study that they strongly agreed with the statement, "I weigh myself often."
When questioned in the followup, 92 percent of those girls said they engaged in some kind of unhealthy weight-control behavior, compared to about 68 percent of girls who strongly disagreed that they weighed themselves frequently.
Unhealthy weight-control behavior could be as minor as skipping an occasional meal. Thirty-eight percent of girls who frequently weighed themselves reported engaging in extreme weight-loss behavior, a higher percentage than for girls who did not weigh themselves often but not enough to be considered statistically significant.
Neumark-Sztainer said the results probably reflect the girls' underlying concern with weight, but even when they adjusted the results for body satisfaction, they still showed a link between frequent weighing and bad eating behavior.
The junior high girls who reported weighing themselves frequently gained an average of 33.3 pounds over five years, compared with just 18.6 pounds for girls their age who didn't weigh in frequently.
There was no statistically significant weight difference among girls who were in high school when they were first surveyed.
The findings were adjusted for race, socio-economic status, weight, body mass index, age and poor body image.
For boys, frequent weigh-ins didn't lead to weight gain, the study found.