How Malnourishment Affects the Brain: Research on Anorexia and Neurobiology

Anorexia’s severe weight loss takes its toll on almost every part of your body, including your brain. But current research suggests that anorexia may be a disorder that starts with an unusual brain structure. Then, as the eating disorder progresses, brain damage deepens.

Understanding the underpinning of anorexia could help researchers find new treatments. And learning that the disorder has a biological beginning could be helpful for people who have long blamed themselves for habits they can’t seem to break.

But this research also highlights why treatment is so important. The damage worsens the longer anorexia persists. If you’re struggling with your eating or watching someone you love struggle, ask for help now.

Is Anorexia a Brain Disorder?

People with anorexia limit food intake and may use methods like excessive exercise to shed pounds. It’s easy to think of anorexia as a body-only condition. But researchers say people with anorexia may have unusual brains, which could influence their thoughts, feelings, and habits regarding eating.

Sensitivity Issues

Our brains are hardwired to recognize both reward and punishment. Chemicals like dopamine are released based on our experiences, and this system functions in an unusual manner in people who develop anorexia.

Researchers say people with anorexia have very active brain activity in response to punishment (like losing a game). But they don’t have the expected response when they experience a reward (like winning). [1]

A sensitivity like this could make someone very sensitive to the following things:

• Compliments based on weight loss
• Teasing due to weight
• Seemingly neutral comments about weight or size

Their brain cells overreact, and adjusting their diets may seem like a great way to respond.

Supercharged Working Memory

Brain cells are designed to hold onto discrete facts for brief periods. This ability allows us to remember our grocery lists, where we put our keys, and other mundane details of daily life. Researchers say this system is overly powerful in people who develop anorexia. [2]

A powerful working memory could make it easy for people with anorexia to set goals and keep them. For example, they tell themselves, “I will only eat a salad at noon.” That mantra sticks with them longer than it might in a healthy person. The working memory makes a poor decision harder to break.

Low Insight

A few essential parts of the brain help us develop self-image and self-esteem. A neighboring region allows us to detect errors in thought or judgment. Researchers say that both of these brain areas are unusual in people with anorexia. [3]

People with poor insight may not see their diet decisions as dangerous. They don’t recognize the error and don’t think they should change.

This trait makes developing anorexia easier. And once anorexia develops, it’s harder to convince someone that they should get treatment for something they don’t see as a mistake.

How Anorexia Affects the Brain

Diet and brain health are closely related. As anorexia deepens and diet changes, people don’t take in the nutrients and calories their brain cells need to stay healthy and work properly. While anorexia may develop due to an unusual brain, the eating disorder can worsen brain health too.

Changes in Reward Systems

Researchers say an ongoing eating disorder can modulate the brain’s reward circuitry. Dopamine that should be released due to a reward (like eating a good meal) is instead released by a punishment (like skipping a snack). [4]

People with anorexia may feel rewarded and happy when they do things that harm their bodies, such as these:

• Reading ingredient labels and finding hidden fat calories
• Exercising excessively
• Pushing food around the plate instead of eating it
• Dropping to an unhealthy weight

Since their brain cells reward them, they may not see the need to change their habits with treatment. Their brain cells tell them they’re making the right choices.

Changing Brain Structure

People with anorexia lose weight everywhere, including inside their brains. Their overall brain volume drops, and parts of the brain thin. Those reductions are very problematic, researchers say, as they suggest people with anorexia are destroying their brain cells or breaking connections between brain areas. [5]

Brain areas typically impacted involve the following: [6]

• Impulsivity
• Attention
• Self-regulation
• Social interactions

Those alterations could make recovering from an eating disorder and making better choices challenging.

Memory Loss

Can anorexia cause memory loss? Researchers think so. Studies suggest that memory loss is part of life for people with anorexia, and it can persist even after people regain weight and enter recovery. [7]

Results like this highlight why treatment is so critical. The sooner people go into care, the less damage the disease will do.

Does Treatment for Anorexia Help?

An anorexia treatment program can’t change your brain structure and cell connections. But you can develop coping skills and understanding. When you know why you’re called to change your diet and understand why changing your habits can be so tricky, you can develop new skills to improve your life.

Since brain changes in anorexia are progressive, early treatment is critical. The sooner you stop harmful eating habits, the less damage you’ll do to your brain cells. So if you’re struggling, now is the time to get help.

Anorexia and Neurobiology FAQs

How does anorexia affect the brain?

Anorexia can cause your brain to shrink, and the chemical signals cells use to signal happiness or harm can change. All these alterations can make your anorexia choices (like skipping meals) seem rewarding, not harmful. However, you may have little insight into why others are worried about your eating and may find it challenging to stick to a traditional healthy diet.

What does anorexia do to the brain?

People with anorexia lose weight all over their bodies, including inside the brain. As your white matter shrinks and your cells lose the ability to communicate clearly, you may struggle to remember details about your daily life. And you may find that your decisions regarding your diet are the only thing that brings you joy.

Your habits may become engrained, all due to changes in your brain.

Can anorexia cause memory loss?

Yes. Memory loss is a well-known and frustrating side effect of anorexia. Some people struggle with memory loss even after they enter treatment and gain weight. A therapy team can help you understand why this happens and teach you how to work around this side effect so you can live a safe and healthy life.

References

1. Weir K. (2016). New Insights on Eating Disorders. American Psychological Association. Accessed September 2022.
2. Rosen M. (2013). The Anorexic Brain. Science News. Accessed September 2022.
3. Abnormalities Found in Insight Areas of the Brain in Anorexia. (2016). UIC Today. Accessed September 2022.
4. Eating Disorder Behaviors Alter Reward Response in the Brain. National Institutes of Health. https://www.nih.gov/news-events/news-releases/eating-disorder-behaviors-alter-reward-response-brain. June 2021. Accessed September 2022.
5. Sheehan ST. (2022). Groundbreaking Study Shows Differences in Brain Structure in People with Anorexia. Keck School of Medicine of USC. Accessed September 2022.
6. Brodrick BB, Adler-Neal AL, Palka JM, Mishra V, Aslan S, McAdams CJ. (2021). Structural Brain Differences in Recovering and Weight-Recovered Adult Outpatient Women with Anorexia Nervosa. Journal of Eating Disorders; 9(108).
7. Nikendei C, Funiok C, Pfuller U, Zastrow A, Aschenbrenner S, Weisbrod M, Herzog W, Friederich H-C. (2011). Memory Performance in Acute and Weight-Restored Anorexia Nervosa Patients. Psychological Medicine; 41(4):829-38.

Last Updated & Reviewed By: Jacquelyn Ekern, MS, LPC on January 30, 2023
Published on EatingDisorderHope.com