Physical Effects of Eating Disorders
Eating disorders (ED) such as anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) are often accompanied by an array of psychological and physiological comorbidities.
By: Krizia Crooke
Eating disorder symptoms can manifest in many ways. Restricting the body nutritionally can deplete multiple organ systems of energy, disrupting vital functioning.¹ When an individual is starved at a cellular level, many physical problems can occur due to malnutrition, including damage to the cardiovascular, gastrointestinal, endocrine, and nervous systems.¹ Other symptoms like hair loss and dry skin may also occur. Understanding how the body responds to starvation can help one navigate nutrition rehabilitation in recovery.
The ‘cave person brain’ is a term used by Dr. Jennifer Gaudiani in her book ‘Sick Enough’ to describe the part of our brain that manages all of the involuntary and functional aspects constantly happening in our bodies each day.¹ This includes functions ranging from blood pressure, digestion, hormone regulation, and basic survival reactions. The ‘cave person brain’ is unaware of external factors and is only aware that the body lacks nutrients and energy.¹ Whether this is due to famine or intentional restriction is unimportant. This term is used throughout the following text to better explain how our bodies react to starvation.
Cardiovascular
Inadequate intake of protein and total calories results in protein-calorie malnutrition. The body responds to inadequate intake by breaking down its own tissue to use as fuel.² Muscle, including cardiac tissue, may be broken down, resulting in a variety of complications, such as reduced heart rate and blood pressure, which, increases the risk of heart failure.³
In individuals with BN, vomiting depletes the body of vital minerals and electrolytes, specifically potassium, which is critical for heart function, making the risk of heart failure a more significant concern.
Gastrointestinal
Gastrointestinal (GI) symptoms are a classic feature in most individuals with EDs and can make recovery particularly difficult. Restricting caloric intake can lead to feelings of fullness after eating even small amounts of food. Additionally, long-term restriction can cause muscle weakness along the GI tract. This, combined with the ‘cave person brain’ mentality, can result in gastroparesis, or slow gastric emptying. During periods of restriction, the ‘cave person brain’ attempts to conserve as much energy as possible by severely restricting smooth muscle movement in the GI tract. By doing this, a mechanism called peristalsis-- which moves food in wave-like motions along the GI tract-- is limited significantly.⁴ Simultaneously, nutrients from our food have an effect on GI hormone release and, in turn, impact appetite.⁵ These changes occur because normal digestion is not essential to survival and the body diverts energy to higher priority systems. As a result, individuals may feel extremely full after consuming small amounts of food. Individuals may often complain about severe bloating, rapid onset of nausea, and even acid reflux-- due to the illusion that the body has consumed a high volume of food.²
Those with BN may damage their esophagus due to excessive vomiting over time, which can result in pain and, in more severe cases, rupture of the esophagus, which is a medical emergency.³ With individuals that engage in purging over a longer period of time, vomiting becomes easier due to the weakening of the esophageal sphincter, which provides a barrier between the stomach and the esophagus.¹ When this sphincter weakens and pressure in the stomach decreases, stomach contents, such as bile and stomach acid, have the ability to leak into the esophagus. This results in a condition known as GERD, gastroesophageal reflux disease, which is associated with the sensation commonly referred to as heartburn. Not only can chronic GERD and exposure to stomach acid increase the risk of developing Barrett’s esophagus, a precancerous condition, and cancer, but it may also be incredibly uncomfortable.¹
Endocrine
Glycogen is the form in which our bodies store excess carbohydrates in our muscles and our liver. It is used as a source of energy when food intake is inadequate. Therefore, food restriction deprives the body of necessary calories and eventually depletes these glycogen stores. Because our brains rely on glucose for energy, we begin to break down muscle into individual amino acids, which can be converted into glucose through a process called gluconeogenesis. Eventually, a significant amount of muscle and fat is lost, leaving the body with no other option besides blood sugar levels to drop. This state of hypoglycemia, or low blood sugar, can be incredibly dangerous and can quickly become a medical emergency.⁴
An area of the brain called the hypothalamus oversees hormone production. EDs can severely impact sex hormones, or estrogen, progestogen, and testosterone. Our ‘cave person brain’ realizes that our bodies are essentially in famine, and intake is too limited to produce a child successfully and safely. Starvation decreases the levels of estrogen and testosterone being produced, which may lead to menstrual abnormalities, a decrease in sexual drive, and bone density loss in more complex situations.⁴
The thyroid gland dictates how the body uses energy and how it responds to other hormones. Thyroid-stimulating hormone (TSH) is made in the brain. It signals the thyroid gland to produce active thyroid hormones T3 and T4, which regulate physiological weight gain/loss, heart rate, mood, and temperature.¹ Thyroid dysfunction is typically diagnosed by a high TSH. However, during times of stress like malnutrition, the thyroid gland is healthy, but TSH levels can vary from low, normal, to slightly elevated, along with a low T3. In more critical cases, T4 will eventually decrease. When excess thyroid hormones are given to an individual who is thought to have a thyroid gland disorder but in actuality has an ED, many medical complications can occur. It can counteract the body’s normal function of slowing down metabolism during starvation, increase bone density losses, and cause a rapid heart rate (tachycardia) on an already strained heart along with increased anxiety.⁴
Nervous
One of the most critical organs affected by an eating disorder is the brain. Studies show that eating disorders, specifically AN, are associated with reduced gray matter.⁶ Gray matter holds all neural cell bodies and nerve synapses. It has a more significant role in our day-to-day functioning.⁵ Nutrients in foods are also precursors to neurotransmitters, which play a prominent role in many processes throughout the body, including drug interactions. Many individuals with EDs have comorbid psychological conditions such as depression, anxiety, and OCD; therefore, need to be adequately nourished for medications to work effectively.⁷
At BALANCE eating disorder treatment center™, our compassionate, highly skilled team of clinicians is trained in diagnosing and treating the spectrum of eating disorders, including anorexia, bulimia, binge eating disorder, compulsive overeating, and other disordered eating and body image issues. 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 a variety of other groups and resources to assist those seeking help for food concerns. Click the button below to learn more about our programs and services.
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This post was written by BALANCE Dietitian, Krizia Crooke (she/her).
Krizia is a Dietetian and graduate student at New York University where she is pursuing her Master’s Degree in Clinical Nutrition. She completed her undergraduate education at Texas Woman’s University, majoring in Nutrition and minoring in Criminal Justice. Krizia plans to work in the realm of eating disorders and is passionate about incorporating the HAES approach into her practice.
References
1. Gaudiani JL. Sick Enough: A Guide to the Medical Complications of Eating Disorders. New York, NY: Routledge; 2019.
2. Birmingham CL, Beumont PJV. Medical management of eating disorders : A practical handbook for healthcare professionals. Cambridge: Cambridge University Press; 2004. http://ebookcentral.proquest.com/lib/nyulibrary-ebooks/detail.action?docID=320905.
3. Health consequences. National Eating Disorders Association Web site. https://www.nationaleatingdisorders.org/health-consequences. Updated 2017. Accessed Oct 18, 2021.
4. Gaudiani JL. Sick Enough: A Guide to the Medical Complications of Eating Disorders. New York, NY: Routledge; 2019.
5. Santonicola A, Gagliardi M, Guarino MPL, Siniscalchi M, Ciacci C, Iovino P. Eating Disorders and Gastrointestinal Diseases. Nutrients. 2019;11(12):3038. Published 2019 Dec 12. doi:10.3390/nu11123038
6. Bang L, Rø Ø, Endestad T. Normal gray matter volumes in women recovered from anorexia nervosa: A voxel-based morphometry study. BMC Psychiatry. 2016;16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866026/. Accessed Oct 23, 2021. doi: 10.1186/s12888-016-0856-z.
7. Fernstrom JD. Dietary precursors and brain neurotransmitter formation. Annu Rev Med. 1981;32:413-425. Accessed Oct 23, 2021. doi: 10.1146/annurev.me.32.020181.002213.