Onset of adolescent eating disorders: population based cohort study over 3 years.
Level 3 - non-randomized controlled study
Prospective population-based cohort study over 3 years
PubMed 10082698 · doi:10.1136/bmj.318.7186.765
What was done
A 3-year prospective cohort study with six waves tracked students initially aged 14–15 years from 44 secondary schools in Victoria, Australia (888 females and 811 males). The study measured height, weight, dieting severity (Adolescent Dieting Scale), psychiatric morbidity (Revised Clinical Interview Schedule), and incident partial-syndrome eating disorders (meeting two DSM-IV criteria for anorexia nervosa or bulimia nervosa via a branched eating disorders test).
What was found
At baseline, partial eating disorder syndromes were present in 3.3% (29/888) of females and 0.3% (2/811) of males. The incidence rate of new eating disorders was 21.8 per 1,000 person-years in females and 6.0 per 1,000 person-years in males. Female severe dieters were 18 times more likely, and moderate dieters 5 times more likely, to develop an eating disorder compared to non-dieters. High psychiatric morbidity independently conferred an almost sevenfold increased risk. After adjusting for prior dieting and psychiatric morbidity, baseline body mass index, extent of exercise, and sex did not independently predict new eating disorders.
Why it matters
This study highlights restrictive dieting and baseline psychiatric distress as primary prospective risk factors for eating disorder onset in adolescents, suggesting that weight management via exercise carries lower risk than dietary restriction.
Limits
The outcome was restricted to partial-syndrome eating disorders (two DSM-IV criteria) rather than full clinical diagnoses. Confidence intervals and exact adjusted hazard ratios for male-specific dieting subgroups were not reported in the abstract.
Cited by
- partial Approximately 30% of people who go on a strict diet develop an eating disorder after reaching their goal weight.