WEDNESDAY, Nov. 6, 2019 (HealthDay News) -- Large, rapid weight loss is the best predictor of medical and psychological problems in patients with atypical anorexia nervosa (AAN), not their body weight at diagnosis, according to a study published online Nov. 5 in Pediatrics.
Andrea K. Garber, Ph.D., R.D., from the University of California in San Francisco, and colleagues examined weight history and illness severity in patients aged 12 to 24 years with anorexia nervosa (66 patients) and AAN (50 patients). Associations between weight history variables and markers of illness severity at admission were examined.
The participants were 91 percent female with an average age of 16.5 years. The researchers observed no differences between the groups for weight history or admission heart rate. In the AAN group, the Eating Disorder Examination-Questionnaire global score was higher. Regardless of admission weight, lower heart rate was associated with faster loss, and lower serum phosphorus was associated with greater amount of weight loss and a longer duration.
"The bigger context is that, over the past 30 years, the prevalence of adolescent obesity has quadrupled, and teens are being told to lose weight without being given tools to do so in a healthy way," a coauthor said in a statement. "Obese teens who adopt unhealthy behaviors -- such as severe food restriction and extreme exercise -- may initially be praised for weight loss or told not to worry about eating-disorder concerns because they aren't underweight. By the time they get to see us, they've lost a tremendous amount of weight, their vital signs are unstable and they need to be hospitalized."