How Eating Disorders Affect the Brain
Eating disorders have a myriad of effects on the body and its organs, particularly the brain and neurological system. Studies show that eating disorders are associated with abnormal neurotransmitter activity, altered stress pathways and reward systems, and even changes in brain matter volume. These aberrations can either be a trigger for disordered eating patterns, a result of these patterns, or both. Eating disorders and their associated alterations in neurological function can give rise to a repetitive cycle of disordered patterns that may be challenging to break away from without proper treatment.
By: Samreen Khan
Edited By: Nicki Parlitsis
Changes in brain function that result from disordered eating may be frustrating for clients because it is not a symptom that is tangible or visible to the outside world. This can perpetuate the sense of “living inside one’s head” and add to the feelings of isolation that often accompany eating disorders.
Unfortunately, the majority of existing studies covering the physiological impacts of eating disorders mainly pertain to more restrictive-type eating disorders such as anorexia and occasionally orthorexia. There is significantly less research on the physiological impacts of other types of eating disorders such as binge-eating disorder and bulimia. However, newer studies have started to explore the neurobiological effects of binge-type disorders in recent years.
Eating disorders are associated with abnormalities in neurotransmitter activity, particularly serotonin and dopamine, both of which play a role in mood regulation. Both anorexia and bulimia nervosa have been associated with a decreased response to serotonin, which can result in dysfunctional appetite, mood, and impulse control.⁴ In particular, undereating is associated with a wide variety of psychological effects such as depression, panic, obsessions and compulsions, social withdrawal, loss of libido, and poor body image. Obsession over food and weight results as a survival effort by the brain, driving the individual to seek out food for proper nourishment. This may show up as a fanatic interest in cooking, recipes, nutrition, and even dreams about food and eating.⁹
Pleasure and reward functions within the brain can be altered as a result of disordered eating behaviors, which can further exacerbate the cycle of eating disordered thoughts. The act of eating itself stimulates the front area of the brain, a site of emotional regulation and reward, which provides a sense of satisfaction. Periods of restriction can cause a type of withdrawal sensation in this area of the brain, leading to an overwhelming urge to binge in order to fulfill the need for adequate nourishment of the body and emotional gratification. In fact, the reward sensation is even greater during periods of intense hunger than when the body is satiated.¹ This can lead to a vicious cycle in individuals with binge-restrict behaviors, driven by a primal response to seek nourishment after periods of restriction.
Eating disorders may be associated with altered production of dopamine, a neurotransmitter that activates pleasure in those same reward systems in the brain. Anorexia, a restrictive eating disorder, is associated with the overproduction of dopamine, leading to feelings of anxiety and the ability to go without food for longer periods of time. Alternatively, bulimia is associated with lower levels of dopamine, which may lead to seeking out food as a way to increase dopamine, and subsequently pleasure, in the body. Binge eating disorder has also been linked to a “hyper-responsiveness to rewards such as food,” which amplifies the satisfaction that results from eating.⁸ Each of these alterations in dopamine production can further fuel the behaviors that are associated with the respective eating disorder.
Delving deeper into anxiety and stress, the hypothalamic-pituitary-adrenal (HPA) axis is another pathway that has been shown to be altered also experiences abnormalities in individuals with eating disorders. This pathway is integral to regulating the body’s stress response and production of cortisol, a stress hormone. In individuals with anorexia and bulimia, the HPA axis is hyperactive⁶, increasing overall stress levels. This only perpetuates the cycles of obsession, reward, and pleasure of eating disordered behaviors such as restricting, binging, and purging to cope with the excess stress.
The most recognized abnormality in eating disordered brains is the volume alterations of gray and white brain matter. Gray matter is the brain area that assists in processing and transmitting information, preserving memories, and regulating movement and emotions. White matter is made up of nerve fiber and insulating material called myelin and allows electrical signals to travel from neuron to neuron to communicate between different regions of the brain.
In individuals with anorexia, due to restriction and malnutrition status, levels of gray matter may be decreased in certain areas that produce an emotional response and foster self-reflection.⁷ These abnormalities can result in impulsive, emotional responses memory impairments, and a distorted perception of the body and self.
On the other hand, white matter increases in many individuals with bulimia and BED. Specifically, these changes occur in the anterior cingulate cortex, which is involved with impulse control and emotion, and the medial frontal cortex, which plays a role in habit formation.² Increased white matter in these areas can contribute to the consistency of eating disordered habits.
Fortunately, various studies have shown that brain matter volume and reward pathways returned to normal in most patients during recovery. The permanent effects of an eating disorder vary from individual to individual, but committing to recovery can reverse many of the damages that are associated with the illness.
At BALANCE eating disorder treatment center™, we offer a variety of programs and services targeted at helping clients overcome disordered eating and develop a healthy relationship with food and their body. In addition to our full-time Day Treatment Program and Weeknight Intensive Outpatient Program, we offer nutrition counseling with a licensed dietitian, meal support, and various other groups and resources to assist those seeking help for food concerns.
Our admissions team would be happy to answer any questions you may have regarding our programs and services. Book a call below, or read more about our philosophy here.
This post was written by BALANCE Blog Contributor, Samreen Khan (she/her/he/him).
Samreen is a senior high school student with an ardent drive to de-stigmatize mental illness and eating disorders. Born and raised in the Bay Area, she experienced the harmful effects of “fitspo” culture firsthand for most of her childhood. Throughout her own recovery journey, she became passionate about deconstructing diet culture and raising awareness about eating disorders in her everyday life. Samreen began extending her own ideology of intuitive eating and body neutrality to others by publishing her own writing online when she was fourteen, and has since received several awards for her prose and poetry. She has conducted research on the biological and evolutionary implications of familial mental illness, and is currently taking college-level Sociology and Psychology courses with hopes to delve further into the social and cultural constructs that bolster disordered eating, especially within marginalized communities. She’s grateful for the opportunity to combine two of her strongest passions — writing and mental health — by working with BALANCE!
This post was edited by BALANCE Dietetic Intern, Nicki Parlitsis (she/her).
Nicki is a Nutrition & Dietetics Masters student at NYU, currently in her Dietetic Internship clinical rotations. She graduated from University of Miami with a Bachelor’s degree in Exercise Physiology and a minor in Sports Medicine. Nicki is currently a virtual personal trainer who uses a weight-inclusive approach to help clients increase their energy, strength, and confidence. When she’s not studying nutrition, she enjoys weightlifting, spending time outdoors, and hanging out with friends. She plans to specialize in helping people navigate the intersection between nutrition, fitness, and disordered eating.
References
Berridge, Kent C. “'Liking' and 'Wanting' Food Rewards: Brain Substrates and Roles in Eating Disorders.” Physiology & Behavior, U.S. National Library of Medicine, 14 July 2009, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717031/.
Finch, Jody. “Do Eating Disorders Impact the Structure of the Brain?” Exchanges, UNC Center of Excellence for Eating Disorders, 4 Aug. 2021, https://uncexchanges.org/2021/08/04/do-eating-disorders-impact-the-structure-of-the-brain/.
Frank, Guido K. W. “Advances from Neuroimaging Studies in Eating Disorders: CNS Spectrums.” Cambridge Core, Cambridge University Press, 23 Apr. 2015, https://www.cambridge.org/core/journals/cns-spectrums/article/abs/advances-from-neuroimaging-studies-in-eating-disorders/AB790BA092B95B3A49F6B88ADC7FAB75.
Kaye, Walter. “Neurobiology of Anorexia and Bulimia Nervosa.” Physiology & Behavior, U.S. National Library of Medicine, 29 Nov. 2007, https://pubmed.ncbi.nlm.nih.gov/18164737/.
Leibowitz, Sarah F. “The Role of Serotonin in Eating Disorders - Drugs.” SpringerLink, Springer International Publishing, 18 Oct. 2012, https://link.springer.com/article/10.2165/00003495-199000393-00005.
Lo Sauro, Carolina, et al. “Stress, Hypothalamic-Pituitary-Adrenal Axis and Eating Disorders.” Neuropsychobiology, Karger Publishers, 13 June 2008, https://www.karger.com/Article/Abstract/138912.
Zhang, Simin, et al. “Psychoradiological Investigations of Gray Matter Alterations in Patients with Anorexia Nervosa.” Nature News, Nature Publishing Group, 13 Dec. 2018, https://www.nature.com/articles/s41398-018-0323-3.
NEDA. “Neurotransmitters.” National Eating Disorders Association, 22 Aug. 2019, https://www.nationaleatingdisorders.org/toolkit/parent-toolkit/neurotransmitters.
NCFED. “The Effects Of Under-Eating.” National Centre for Eating Disorders, 2 Sept. 2019, eating-disorders.org.uk/information/the-effects-of-under-eating.