July 13, 2026, 6:44 pm | Read time: 4 minutes
Relapses are among the biggest challenges in anorexia, even after successful treatment. Why is that? French researchers have now discovered a mechanism that not only helps to better understand anorexia but also potentially points to more successful therapies. FITBOOK explains why the current study could be a milestone in the fight against this deadly disease.
Anorexia nervosa is one of the deadliest mental illnesses (as reported by FITBOOK). Despite completing therapy successfully, about one-third of those affected experience a relapse within a year. And this happens despite their will to live. How can this be? Researchers have long suspected that a dysregulation of certain “hunger-satiety hormones” significantly complicates long-term therapy success.
Researchers at Université Paris Cité wanted to examine whether this hormone system is also linked to certain thinking and decision-making processes, which could explain why some patients remain stable in the long term while others do not. Their research findings were recently published in the journal “Translational Psychiatry.”1
Why anorexia is so difficult to treat
Many still believe that anorexia can be managed with a little self-discipline, regular meals, and reaching a healthy weight. At the same time, those who relapse are often accused of lacking willpower. Psychiatrists, psychologists, and neuroscientists have long agreed that the disease is much more complex. Apparently, patients must fight against their own imbalanced hormones, which prove to be extremely strong adversaries. Since there are currently no approved medications, researchers hoped for new insights for more sustainable therapies.
Studies on female patients and mice
Although men can also suffer from anorexia, it predominantly affects young women. The first part of the study included 30 women aged 18 to 60 diagnosed with anorexia nervosa. They completed a four-month nutrition program at a specialized eating disorder clinic. The patients filled out detailed questionnaires about their behavior before, after, and six months later, and provided blood samples. Researchers measured the levels of the hormones ghrelin and LEAP2, which in healthy individuals are responsible for appetite and subsequent satiety.
Additionally, the researchers studied female mice. These mice were initially given only 50 percent of their normal food intake for 15 days, resulting in a 25 percent weight loss. They were then fed normally for ten days. The researchers observed whether and how their behavior and blood values changed.
When one’s own hormones hinder the path to recovery
The researchers discovered a significant pattern. Patients had about 20 percent higher hunger-suppressing LEAP2 levels upon their initial hospital admission than after four months of treatment, during which they regained weight. Those with the highest LEAP2 levels had a higher risk of an anorexia relapse. In contrast, those who managed to maintain their weight showed better-normalized levels. While ghrelin alone was not very informative, the ratio of ghrelin to LEAP2 proved to be a crucial factor for stability after discharge.
In mice, food scarcity led them to prefer small immediate rewards over larger delayed ones. Interestingly, the mice reacted differently than the patients: Under hunger, their LEAP2 levels dropped, and they became more impulsive–seeking immediate rewards. The observed changes in the dopamine system could not explain these effects, suggesting that other unknown mechanisms are involved.
A relapse into anorexia is not due to a lack of willpower
According to the researchers, hunger hormones apparently influence not only appetite but also how the brain makes decisions. During anorexia, this connection seems disrupted, but after successful weight gain, it could at least partially normalize. The hormone LEAP2, produced by the liver and intestines, counteracts the “appetite-stimulating” ghrelin and suppresses the body’s hunger signals.
Different Effects of Fructose and Glucose on the Brain
Certain Intestinal Bacteria Causes Sugar Cravings
Battle against one’s own hormones?
The study offers an intriguing new perspective on the role of metabolic hormones in the recovery or relapse of anorexia. “Our findings suggest that hormones that normally regulate hunger and satiety behave differently in people with anorexia,” explains study leader Dr. Virginie Tolle in a statement.2 She hopes that LEAP2 will help in the future to detect relapses early and better tailor therapies. The results from the mouse model suggest that LEAP2 may play a crucial role in the body’s adaptation to prolonged periods of food scarcity. These are important insights. However, the disease cannot be fully replicated in rodents, the researchers emphasize.
Also of interest: How can parents recognize if their child has anorexia–and how can they help?
Connections, but no cause yet
The clinical study included only 30 patients, which limits its significance. Additionally, psychological symptoms were not fully considered, as weight is just one of many factors. To translate these initial promising findings into practical applications that prevent relapses and save lives, significantly larger clinical studies are needed. Applying the first new techniques in a follow-up study with a larger patient group is already in planning, it is concluded.