Why Full Anorexia Recovery Is Crucial for Brain Health

illustration of a brain

John Lund / Getty Images

Anorexia nervosa (AN) is an illness defined by restriction of food, often resulting in malnutrition. Malnutrition affects every system of the body, and the brain rarely escapes malnutrition’s impact. 

Brain Changes Related to Anorexia Nervosa

AN is accompanied by changes in mood and thinking. Patients frequently have symptoms of anxiety and depression that do not predate the eating disorder or are exacerbated by the AN. Ancel Keys’ Minnesota Study documented that anxiety and depression were among the symptoms that presented in healthy men put on a semi-starvation diet.

Additionally, individuals with AN often withdraw socially, become more rigid and fixated in their thinking, and frequently have little insight into their illness.

One parent described her daughter, “As if the physical decline was not scary enough, she became a different and frightening person. She would lie and manipulate in order to get out of eating and get her workouts in. She would lie and manipulate to explain away the increasing isolation from friends. When I did attempt to ‘just get her to eat,’ my report to my husband about how it went would be, ‘Her head spun around three times Exorcist-style and venom began to spew from her mouth.’”


There is a general agreement that recovery from AN requires weight restoration and nutritional rehabilitation. This must be prioritized over insight-focused therapeutic work. Three recent studies on the brain serve to illustrate why this is so important.

A study by Roberto and colleagues (2010) used MRI imaging techniques to study the brains of 32 adult women with AN before and after weight restoration (to 90 percent of their ideal body weight) and compared them to the brains of 21 women who did not have AN. The results showed:

  • Underweight individuals with AN had significant deficits in brain gray matter volume compared to healthy controls.
  • These deficits in gray matter volume improved with short-term weight restoration but did not fully normalize over the course of the 51-week study.
  • Researchers concluded: “The correlation between BMI and volume changes suggests that starvation plays a central role in brain deficits among patients with AN, although the mechanism through which starvation impacts brain volume remains unclear.”

A study by Wagner and colleagues (2005) performed MRI brain scans on 40 women in long-term recovery from eating disorders (subjects included patients with both AN and bulimia nervosa). Their length of recovery ranged from 29 to 40 months (much longer than the Roberto study). Results showed:

  • All brain structures in the recovered women were normal in volume and similar to those of control subjects.
  • This study suggests that structural brain abnormalities are reversible with long-term recovery.

A study by Chui and colleagues (2008) evaluated 66 adult women with a history of adolescent-onset AN and compared them to 42 healthy female women. The participants received an MRI and cognitive evaluation. The results showed:

  • Participants with AN who remained at low weight had abnormal MRI scans.
  • Weight recovered patients had normal brain volumes.
  • Participants who currently had lost their menstrual cycles or had irregular menses showed significant deficits across a broad range of many cognitive domains including verbal ability, cognitive efficiency, reading, math, and delayed verbal recall (even if the structural brain changes had resolved).

Brain Recovery After Anorexia

Taken together, these studies suggest a complex interplay between weight status, brain structure, and optimal brain functioning. Brain matter actually shrinks during AN and takes time to recover. Six months after full weight restoration the brain often is not yet structurally back to normal. Yet with enough time at a healthy weight, the brain seems to fully recover. The research suggests that by three years after achieving weight recovery, most individuals’ brains will likely appear normal physically.

However, even though a brain post-weight restoration may look normal, normal brain functioning may not yet have returned. It seems that menstrual function may be a mediator and a better predictor of cognitive recovery than weight (for females) and that full cognitive functioning may not return until menstruation has been maintained for at least six months. This is one reason why the return of and continued menses is such an important marker of recovery.

Parents of patients with anorexia report a range of time, from six months to two-plus years for full “brain healing” to occur. What parents usually mean when they report brain healing is that they notice an improved state, “like the patient is coming out of a fog.” Furthermore, parents report that brain healing brings around changes in mood and behaviors such that patients seem more stable in their recovery and “back to their former (pre-illness) selves.” One book for parents is even entitled, “My Kid Is Back.”

It is important to recognize the catch-22 of AN recovery. Individuals with AN are typically cognitively impaired and require sustained time at a healthy weight for cognitive impairments to fully improve. Yet, it is partly the cognitive symptoms of AN that make sufferers believe there is “nothing wrong” with them and thus reject treatment, which is a condition called “anosognosia.”

Implications for Patients and Families

The upshot of this research, according to Dr. Ovidio Bermudez, MD, Chief Clinical Officer and Medical Director of Child & Adolescent Services at Eating Recovery Center in Denver, is that that parents and treatment professionals cannot afford to compromise on weight gain. Dr. Bermudez lectures that ill underweight patients need a “brain rescue” so that “psychotherapy and behavior change can make a difference.”

This is likely one reason that family-based treatment (FBT) is often more successful than individual therapy for younger patients. Parents often need to do the heavy lifting for their children who are malnourished. It also illustrates the challenge of treatment for older patients with anorexia who may be trying to achieve recovery with a starved brain. Research supports that only with full and sustained weight restoration are individuals fully able to maintain their own recovery.

4 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kalm LM, Semba RD. They starved so that others be better fed: remembering Ancel Keys and the Minnesota experiment. J Nutr. 2005;135(6):1347-52. doi:10.1093/jn/135.6.1347

  2. Roberto CA, Mayer LE, Brickman AM, et al. Brain tissue volume changes following weight gain in adults with anorexia nervosa. Int J Eat Disord. 2011;44(5):406-11. doi:10.1002/eat.20840

  3. Wagner A, Greer P, Bailer UF, et al. Normal brain tissue volumes after long-term recovery in anorexia and bulimia nervosa. Biol Psychiatry. 2006;59(3):291-3. doi:10.1016/j.biopsych.2005.06.014

  4. Chui HT, Christensen BK, Zipursky RB, et al. Cognitive function and brain structure in females with a history of adolescent-onset anorexia nervosa. Pediatrics. 2008;122(2):e426-37. doi:10.1542/peds.2008-0170

By Lauren Muhlheim, PsyD, CEDS
 Lauren Muhlheim, PsyD, is a certified eating disorders expert and clinical psychologist who provides cognitive behavioral psychotherapy.