A new Australian study finds that 31 percent of adolescents hospitalized for anorexia nervosa exhibit all the cognitive and physical complications of the disease without being underweight.

Dietitian Melissa Whitelaw at the University of Melbourne is calling for a change to the diagnostic criteria for the disorder after finding that patients with “atypical anorexia” suffer serious health concerns despite being within or even above the healthy weight range.

“What we are seeing now is that you can have a healthy body weight but be just as sick as someone with typical anorexia nervosa, including having the same thoughts about eating and food,” said Whitelaw.

“We need to redefine anorexia because an increasing proportion of anorexia nervosa patients are atypical and more difficult to recognise. The definition should refer to weight loss, not just underweight.”

For the study, Whitelaw looked at 171 anorexia patients, ages 12 to 19, who were admitted to the Royal Children’s Hospital’s eating disorder program in Melbourne, Australia between 2005-2013.

She found the following:

  • 51 of the patients were “atypical” with significant eating disorder psychopathology, but not underweight;
  • Rather than being underweight, greater weight loss was associated with life threateningly low pulse rates, a complication of starvation in anorexia nervosa that requires admission;
  • Patients with atypical anorexia also suffered low blood pressure and deranged blood electrolytes;
  • Importantly, no complication was independently associated with being underweight, the typical hallmark symptom of anorexia;
  • None of the patients in the study were being monitored by a health professional for weight loss, their relationship with food, or their methods of losing weight.

Atypical anorexia patients might have lost about a quarter of their body weight, but the body can go into “starvation mode” if as little as 10 percent of weight was lost quickly, causing the heart rate to slow in order to preserve energy.

According to Whitelaw, atypical patients may have been encouraged by family or health professionals to lose the weight. This frequently results in praise and encouragement about how good they look, re-enforcing even more weight loss.

“If adolescents lose weight, it doesn’t matter what weight they are, a health professional should monitor them to check that weight loss is appropriate and if so, that it is done gradually,” said Whitelaw.

“They should also monitor the adolescent’s dietary intake and relationship with food and exercise for signs the patient was spiralling into an eating disorder. Following large amounts of weight loss, careful medical assessment is also recommended.”

Once a person goes into starvation mode the only way to increase the heart rate is re-feeding and weight gain, which in this cohort, required hospitalization.

Whitelaw said people can understand an extremely thin patient needing to gain weight, but it is often a shock to patients and families when someone within or above the healthy weight range needs to gain weight.

And while atypical anorexia nervosa is often seen as less severe than anorexia nervosa, the new findings show that the health consequences can be just as dangerous. Whitelaw believes it is time to change the current diagnostic criteria which states that those with anorexia nervosa must be underweight.

“The face of eating disorders is changing against a backdrop of increasing prevalence of overweight and obesity. Families, teachers, sports coaches and others interacting with young people should not delay seeking help for adolescents with worrying eating patterns if they have lost weight, even if they are not underweight,” said Whitelaw.

The new findings are published in the Journal of Adolescent Health.

Source: University of Melbourne