Reviewed by Kim Dennis, MD, CEDS
Eating disorders are serious, potentially life-threatening conditions that affect a person’s emotional, physical, social, and spiritual health. They are not just a “fad” or a “phase.” People do not just “catch” an eating disorder for a period of time. They are real, complex, and devastating conditions that can have serious consequences for health, productivity, and relationships.1
Eating disorders can affect every organ system in the body and for some people these illnesses are fatal. The earlier a person with an eating disorder seeks treatment, the greater the likelihood of full physical and emotional recovery.1
Common Health Consequences of Eating Disorders:1
- Consuming fewer calories than you need means that the body breaks down its own tissue to use for fuel. Muscles are some of the first organs broken down, and the most important muscle in the body is the heart. Pulse and blood pressure begin to drop as the heart has less fuel to pump blood and fewer cells to pump with. The risk for heart failure rises as the heart rate and blood pressure levels sink lower and lower.
- Some physicians confuse the slow pulse of an athlete (which is due to a strong, healthy heart) with the slow pulse of an eating disorder (which is due to a malnourished heart). If there is concern about an eating disorder, consider low heart rate to be a symptom.
- Purging by vomiting or laxatives depletes your body of important chemicals called electrolytes. The electrolyte potassium plays an important role in helping the heartbeat and muscles contract but is often depleted by purging. Other electrolytes, such as sodium, magnesium, calcium, and chloride, can also become imbalanced by eating disorder behaviors such as restriction, purging, avoiding fluids or by drinking excessive amounts of water. Electrolyte imbalances can lead to irregular heartbeats and possibly heart failure and death.
- Eating disorders can lead to reduced resting metabolic rate, a result of the body’s attempts to conserve energy after periods of nutrient restriction; conversely, some people may experience a paradoxical increase in metabolic rate as they begin to renourish. A doctor with eating disorder experience will be able to determine your level of risk and what level of care would be safest to begin your recovery. Consultation with an eating disorder specific dietician, doctor, and therapist can help you renourish with the least chance of experiencing complications.
- Slowed digestion known as gastroparesis. Food restriction and/or purging by vomiting interferes with normal stomach emptying and the digestion of nutrients, which can lead to:
- Stomach pain and bloating
- Nausea and vomiting
- Blood sugar fluctuations
- Blocked intestines from solid masses of undigested food
- Bacterial infections
- Feeling full after eating only small amounts of food
- Constipation, which can have several causes:
- Inadequate nutritional intake, which means there’s not enough material in the intestines for the body to eliminate.
- Long-term inadequate nutrition can weaken the muscles of the intestines and leave them without the strength to propel digested food out of the body.
- Laxative misuse can damage nerve endings and leave the body dependent on them to have a bowel movement. Sometimes this leads to a colon that can’t contract bowel muscles on its own.
- Binge eating can cause the stomach to rupture, creating a life-threatening emergency.
- Vomiting can wear down the esophagus and cause it to rupture, creating a life-threatening emergency.
- Frequent vomiting can also cause sore throats, a hoarse voice or ulcers.
- When someone makes themselves vomit over a long period of time, their salivary (parotid) glands under the jaw and in front of the ears can get swollen. This can also happen when a person stops vomiting.
- Intestinal obstruction, perforation, or infections, such as:
- Mechanical bowel problems, like physical obstruction of the intestine, caused by ingested items.
- Intestinal obstruction or a blockage that prevents food and water from passing through the intestines.
- Bezoar, a mass of indigestible material found trapped in the gastrointestinal tract (esophagus, stomach, or intestines).
- Intestinal perforation, caused by the ingestion of a nonfood item that creates a hole in the wall of the stomach, intestines or bowels.
- Infections such as toxoplasmosis and toxocariasis may occur because of ingesting feces or dirt.
- Poisoning, such as heavy metal poisoning caused by the ingestion of lead-based paint.
- Both malnutrition and purging can cause pancreatitis, an inflammation of the pancreas. Symptoms include pain, nausea, and vomiting.
- Food restriction or repeated binge eating episodes can cause liver inflammation
- Although the brain makes up a relatively small percentage of total body mass, it consumes up to one-fifth of the body’s calories. Dieting, fasting, self-starvation, and/or erratic eating means the brain isn’t getting the energy it needs, which can lead to obsessing about food and difficulties concentrating.
- Extreme hunger or fullness at bedtime can create difficulties falling or staying asleep.
- The body’s neurons require an insulating, protective layer of lipids to be able to conduct electricity. Inadequate fat intake can damage this protective layer, causing numbness and tingling in hands, feet, and other extremities.
- Neurons use electrolytes (potassium, sodium, chloride, and calcium) to send electrical and chemical signals in the brain and body. Severe dehydration and electrolyte imbalances can lead to seizures and muscle cramps.
- If the brain and blood vessels can’t push enough blood to the brain, it can cause fainting or dizziness, especially upon standing.
- The body makes many of its needed hormones with the fat and cholesterol we eat. Without enough fat and calories in the diet, levels of hormones can fall, including:
- Sex hormones estrogen and testosterone
- Thyroid hormones
- Lowered sex hormones can cause menstruation to fail to begin, to become irregular, or to stop completely.
- Lowered sex hormones can significantly increase bone loss (known as osteopenia and osteoporosis) and the risk of broken bones and fractures.
- Lowered sex hormones can diminish sex drive and sexual functioning.
- Over time, repeated binge eating episodes can potentially increase the chances that a person’s body will become resistant to insulin, a hormone that lets the body get energy from carbohydrates. This can lead to Type 2 Diabetes.
- Without enough energy to fuel its metabolic fire, core body temperature will drop and hypothermia may develop.
- Starvation can cause high cholesterol levels, due to disruptions in lipid metabolism. This is NOT an indication to restrict dietary fats, lipids, and/or cholesterol, which could worsen the problem.
Other Health Consequences
- Low caloric and fat consumption can cause dry skin, and hair to become brittle and fall out.
- To conserve warmth during periods of starvation, the body will grow fine, downy hair called lanugo.
- Severe, prolonged dehydration can lead to kidney failure.
- Inadequate nutrition can decrease the number of certain types of blood cells.
- Anemia develops when there are too few red blood cells or too little iron in the diet. Symptoms include fatigue, weakness, and shortness of breath.
- Malnutrition can also decrease infection-fighting white blood cells.
- Purging by vomiting can be associated with tooth enamel loss and cavities.
Mortality and Eating Disorders
While it is well known that anorexia nervosa is a deadly disorder, the death rate varies considerably between studies. This variation may be due to length of follow-up, or ability to find people years later, or other reasons. In addition, it has not been certain whether other subtypes of eating disorders also have high mortality. Several recent papers have shed new light on these questions by using large samples followed up over many years. Most importantly, they get around the problem of tracking people over time by using national registries which report when people die. A paper by Papadopoulos studied more than 6000 individuals with AN over 30 years using Swedish registries.2 Overall people with anorexia nervosa had a six-fold increase in mortality compared to the general population. Reasons for death include starvation, substance abuse, and suicide. Importantly the authors also found an increased rate of death from ‘natural’ causes, such as cancer.
It has not been certain whether mortality rates are high for other eating disorders, such as bulimia nervosa and other specified feeding or eating disorder (OSFED), the latter of which is the most common eating disorder diagnosis. Crow and colleagues studied 1,885 individuals with anorexia nervosa (N=177), bulimia nervosa (N=906), or eating disorder not otherwise specified (N=802) over 8 to 25 years.3 The investigators used computerized record linkage to the National Death Index, which provides vital status information for the entire United States, including cause of death extracted from death certificates. Crow and colleagues found that crude mortality rates were 4% for anorexia nervosa, 3.9% for bulimia nervosa, and 5.2% for eating disorder not otherwise specified. They also found a high suicide rate in bulimia nervosa. The elevated mortality risks for bulimia nervosa and eating disorder not otherwise specified were similar to those for anorexia nervosa.3
A study published in 2022 has also shown that death rates are significantly increased when people with eating disorders also use substances. This is alarming because substance use disorder have the highest premature mortality rates of any mental illness, with anorexia nervosa having the second highest. For patients with anorexia who use drugs, risk of premature death increases up to 22-fold compared with matched control subjects.4
In summary, these findings underscore the severity and public health significance of all types of eating disorders.
Special thank you to Walter Kaye, MD, Professor of Psychiatry, Director, UCSD Eating Disorder Research and Treatment Program, University of California, San Diego