Treating Anorexia with a Smartphone App

A study published today in Frontiers in Neuroscience suggests that eating disorders should be considered just that—eating disorders. In fact, attempts to treat anorexia as a mental illness have largely failed.

“Anorexic patients can normalize their eating rate by adjusting food intake to feedback from a smartphone app,” says first author Per Sodersten of the Karolinska Institute. “And in contrast to failing standard treatments, most regain a normal body weight, their health improves, and few relapse.”

The approach presented in the study is based on the theory that slow eating and excessive physical exertion, both hallmarks of anorexia, are evolutionarily conserved responses to short food supply that can be triggered by dieting and reversed by practicing normal eating.

“This new perspective is not so new: nearly 40 years ago, it was realized that the conspicuous high physical activity of anorexia is a normal, evolutionarily conserved response—i.e., foraging for food when it is in short supply—that can be triggered dietary restriction,” Sodersten notes. “In striking similarity to human anorexics, rats and mice given food only once a day begin to increase their running activity and decrease their food intake further to the point at which they lose a great deal of body weight and can eventually die.”

More recently, the theory has been elaborated and validated by studies of brain function. “We find that chemical signaling in the starved brain supports the search for food, rather than eating itself,” Sodersten reports.

To prove that the evolutionary perspective works in practice, Sodersten and team provide eating disorders services in Sweden.

“Subjects eat food from a plate that sits on a scale connected to their smartphone. The scale records the weight loss of the plate during the meal, and, via an app, creates a curve of food intake, meal duration, and rate of eating,” explains Sodersten. “At regular intervals, a rating scale appears on the screen and the subject is asked to rate their feeling of fullness.”

The patients are also given reference curves of the eating behavior and feeling of fullness of healthy controls, helping them to adapt their behavior in real time. With this feedback, patients learn to visualize what normal portions of food look like and how to eat at a normal rate.

The method has now been used to treat over 1500 patients with significant success.