Adolescents who diet and develop eating disorders carry these unhealthy practices into young adulthood and beyond, University of Minnesota researchers found. Lead investigator Dianne Neumark-Sztainer, a professor at the School of Public Health at the University of Minnesota, and colleagues used data from a 10-year longitudinal study aimed at examining eating, activity and weight-related variables among young people. The researchers examined the records for 1,030 men and 1,257 women -- one-third of participants had a mean age of 12.8 years at the beginning of the study. Two thirds of participants were in middle adolescence with a mean age of 15.9 at the beginning of the study. The study, scheduled to be published in the July issue of the Journal of the American Dietetic Association, found about one-half of the females reported dieting in the past year compared to about one-fourth of the males, and this remained fairly constant from adolescence through young adulthood for females in both age groups. Among males, the prevalence of dieting stayed constant over time but significantly increased in the older cohort as they progressed from middle adolescence to middle young adulthood. Among older females, unhealthy weight control behaviors showed a statistically significant decrease from middle adolescence (60.7 percent) to middle young adulthood, but still remained very high at 54.4 percent. About one-third of the males reported unhealthy weight control behaviors, which remained fairly constant over the length of the study.