[Perceived or BMI-measured overweight and weight control behaviors in undergraduate adolescents from Ciudad Guzman, Jalisco, Mexico]

The aim was to evaluate associations between weight control behaviors and overweight measured by BMI, overweight perception or inaccurate weight perception. 492 undergraduate adolescents from 17 to 19 years old participated in the study. A self-administered questionnaire on line was applied and weight and height were measured. Statistical analysis included weighted kappa and multivariate logistic regression. The concordance between weight perception and that evaluated by BMI was 78.7%, weight kappa = 0.62. Adolescents who perceived overweight tried to lose weight, exercised and ate less food more frequently than those who were overweight evaluated by BMI. A quarter tried to lose weight eventhough they did not perceive or were actually overweight. The odds of trying to lose weight were higher in men and women who perceived overweight (OR = 18.7, CI 95% 6.3-55.3 and OR = 10.4, IC 95% 4.5-24.2, respectively) andwomen who overestimated overweight (OR = 6.0, CI 95% 2.8-12.7). The odds of tying to lose weight when weight was underestimated were less in men (OR = 0.03, CI 95% 0.01-0.12) and women (OR = 0.19, IC 95% 0.05-0.70). In conclusion the behavior of trying to lose weight was better explained among adolescents of both genders who perceived overweight and among girls who overestimated it