Prevalence and correlates of self-induced vomiting as weight-control strategy among adolescents in Taiwan

Abstract

Aims: This study was designed to assess the prevalence and correlates of self-induced vomiting to control body weight among adolescents in Taiwan.

Background: Over the past decades, the rate of obesity among children in Taiwan has nearly tripled. Educational authorities have devoted considerable effort to prevent the increase in childhood obesity.

Design: An observational exploratory design to investigate the problem of using unhealthy weight-reduction strategy.

Methods: This study consists of a cross-sectional study aimed at collecting national representative data. We chose 120 representative schools using a three-stage stratified systematic sampling design with probability proportionate to the size of the population in Taiwan. Participants consisted of 8673 girls and 7043 boys, aged 10-18 old.

Results: Of the participants, 13% reported using self-induced vomiting, the prevalence being highest in participants aged 10-12 (15·9%) and lowest in participants aged 16-18 (7·5%). Several factors were significantly and positively associated with the use of self-induced vomiting as a weight-loss strategy, specifically subjects who (1) watched television, used computer, surfed the Internet or played video games for greater than or equal to two hours/day, (2) consumed fried food every day and (3) ate night-time snacks every day (odds ratio = 1·55, 2·10 and 1·51, respectively; p < 0·05). Eating breakfast every day and sleeping for more than eight hours a day were both protective factors against the use of self-induced vomiting to control body weight (odds ratio = 0·43 and 0·86, respectively; p < 0·05).

Conclusions: Self-induced vomiting was prevalent among adolescents who had tried to lose weight; sedentary lifestyle, shorter sleep length and unhealthy eating habits may contribute significantly to this behaviour among these adolescents.

Relevance to clinical practice: School nurses who are helping adolescents lose weight should also pay attention to the possibility they are using self-induced vomiting as a weight-control strategy.