Weight Gain Predicts Psychological Improvement in Anorexia Nervosa

A recent study published in the journal Behavior Research and Therapy demonstrated that weight gain was a significant predictor of improved psychological functioning in adolescents undergoing treatment for anorexia nervosa (AN). In other words, adolescents who gained more weight during treatment did better mentally than those who gained less weight. This study also showed that weight gain early in the course of treatment had a greater impact on psychological recovery than weight gain later in the course of treatment.

This finding is extremely relevant not only to clinicians who treat adolescent AN, but also to the adolescent patients themselves and their families. The process of re-feeding and restoring weight often feels agonizing for patients and may cause tremendous stress to caregivers. Psychological recovery lags behind physical recovery, so patients often feel worse before they start to feel better. This study provides objective evidence that it is in the patient’s best interest – both physically and psychologically – to eat more and gain weight as soon as possible after diagnosis.

Weight gain is an essential component of treatment for patients with AN. The knowledge that full nutrition is necessary to repair the physical damage caused by AN – including weakened heart, low blood pressure, hypothermia, osteoporosis, stress fractures, lanugo, amenorrhea, infertility, and risk of premature death – helps many patients and families to persevere through the difficult days of re-feeding. Now, patients and families can hold onto hope that weight restoration will bring about psychological improvement as well. This study provides families with direct scientific evidence that gaining weight gives their loved one a greater chance of recovering mentally, emerging from the fog of depression, and reclaiming a meaningful life free from food and weight preoccupation.

Patients in this study were randomly assigned to receive either Family-Based Treatment (FBT) or Adolescent Focused Treatment (AFT). The authors of this study found that weight gain predicted psychological recovery regardless of the type of treatment (FBT vs. AFT) the patient received. This finding may be especially relevant to clinicians who treat adolescent AN using individual therapy. A common criticism of FBT (usually made by clinicians who reject FBT without really understanding it) is that it focuses on weight gain at the expense of the adolescent’s psychological wellbeing. This study clearly demonstrates that weight gain and improved psychological functioning are not mutually exclusive. On the contrary, weight gain and improved psychological functioning are strongly correlated!

It is clear that FBT supports the adolescent’s psychological wellbeing indirectly by promoting regular nutrition and steady weight gain, which help to repair the brain damage caused by malnutrition. I would also argue that FBT has a direct impact on the adolescent’s psychological wellbeing by externalizing the illness, removing any sense of self-blame the adolescent may have, supporting her emotionally, and relieving her of the burden of fighting this deadly illness alone.