“As a society that is so heavily influenced by diet culture, our relationships with our bodies can be dysfunctional,” said Jamal Essayli, assistant professor of pediatrics and of psychiatry and behavioral health. “I came out as gay in high school, and by the time I got to college, I noticed an increased emphasis on body image among gay men. That’s partly what inspired my interest in researching and working with patients with eating disorders.”

According to the National Eating Disorders Association, approximately 30 million Americans will struggle with eating disorders, including anorexia nervosa, bulimia nervosa, binge-eating disorder and others, at some point in their lives. In addition to the LGBTQ+ community, adolescents and young adults are particularly vulnerable, and the COVID-19 pandemic didn’t help. Recent research by co-author Jennifer Shook, assistant professor of pediatrics at the Penn State College of Medicine, and others demonstrated a significant increase in eating disorder-associated inpatient and outpatient visits to emergency departments among adolescents and young adults during the pandemic.

“While this is an active area of research, the causes of eating disorders are typically thought to be a combination of biological predisposition and environment,” said Essayli. “For example, having an anxious or perfectionistic predisposition and being teased about your body size or weight can both increase a person’s risk for developing an eating disorder.”

In the current study, which was published in the International Journal of Eating Disorders, Essayli and his colleagues recruited 54 adolescents with a median age of 14 years who were participating in a partial hospitalization program for eating disorders. The program ran five days a week for an average of eight weeks per individual. Each day, the clinical team exposed the patients to a feared food. For example, participants were given a full-sized candy bar on Mondays, a baked good such as a cookie on Tuesdays, pizza on Wednesdays, a dessert on Thursdays and a breakfast item such as pancakes on Fridays.

“Many of these patients were underweight or weight suppressed, and had intense anxiety about these foods,” said Essayli. “It was important for them to learn that there’s nothing horrible about having pizza and ice cream at a party, for example, that it’s actually part of a fulfilling life.”

Patients provided subjective units of distress (SUDS) ratings on a scale from 0 (no distress) to 10 (extremely high distress) immediately before and after each food exposure. In addition, patients were periodically given the Children’s Eating Attitudes Test and Fear of Food Measure, which are aimed at determining levels of anxiety about eating and food avoidance behaviors. Finally, the adolescents were encouraged to discuss their feelings about the exposure challenges in weekly therapy sessions.

“One of the things we wanted to test was whether within-session and between-session habituation were important for weight gain,” said Essayli. “Say, you’re afraid of dogs. If you’re doing exposure therapy by spending time around a dog, within-session habituation is when your anxiety decreases while you’re with the dog. Between-session habituation is when your anxiety decreases from session to session across days.”

This distinction is important, Essayli said, because the extent to which clinicians should emphasize or disregard fear-reduction during exposure therapy sessions for eating disorders was previously unknown.

Overall, the team found that SUDS decreased significantly over time prior to exposure to feared foods, providing some evidence that between-session habituation occurred. However, the difference between pre-exposure and post-exposure SUDS did not decrease over time, indicating that within-session habituation did not occur. Therefore, the team concluded that between-session habituation, but not within-session habituation, predicted favorable treatment outcomes, including weight gain and improvements on the Children’s Eating Attitudes Test and Fear of Food Measure.

“Our findings provide support for integrating food exposure into partial hospitalization programs for adolescents with eating disorders who are undergoing weight restoration,” said Essayli. “And while more research is needed, our results may begin to help clinicians determine how much emphasis to place on within-session habituation and between-session habituation.”

Other Penn State authors on the paper include Lauren Forrest, assistant professor of psychiatry and behavioral health; Kathleen Keller, professor of nutritional sciences and food science; and Susan Lane-Loney, associate professor of pediatrics and of psychiatry and behavioral health. Hana Zickgraf, assistant professor of pediatrics, Emory University, and Emily Stefano, assistant professor, Bariatric and Weight Management Center, Wake Forest University, also are authors.

The National Institutes of Health supported this research.