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  • Krisha Janaswamy

The Effects of Eating Disorders on the Human Body

- Krisha Janaswamy

Eating disorders are a serious mental illness, characterized by eating, exercise and body weight/shape becoming an unhealthy preoccupation of someone’s life. They are not a lifestyle choice, a cry for attention, a diet gone wrong or a fad. They are real, devastating illnesses that can have serious effects on the person's’ health, productivity and relationships. Most people with eating disorders do not realise that they are ill, and those that do go to extraordinary lengths to hide the signs.

The Diagnostic and Statistical Manual of Mental Disorders 5 recognises seven eating disorders, including Pica, Rumination Disorder, Avoidant/Restrictive Food Intake Disorder, Anorexia Nervosa, Bulimia Nervosa, Binge-Eating Disorder, Other Specified Feeding or Eating Disorder and Unspecified Feeding or Eating Disorder.

Behavioural symptoms that may be indicative of eating disorders include:

  • Constant or repetitive dieting

  • Skipping meals or making excuses for not eating

  • Significant weight loss

  • Significant nutritive deficiency

  • Intense fear of gaining weight or of becoming fat, or persistent behaviour that interferes with weight gain, even if at a low weight

  • Social withdrawal

  • Calluses on the knuckles from induced vomiting

  • Loss of enamel which may be a sign of repeated vomiting

  • Making lists of ‘good’ and ‘bad’ foods

  • Leaving frequently during meals to use the toilet

  • Frequently checking in the mirror for perceived flaws

  • Self-image is unduly influenced by body shape, weight and appearance

  • Recurrent inappropriate compensatory behaviours to prevent weight gain such as vomiting, misuse of laxatives, diuretics and other medication

  • Fasting

  • Excessive exercise

Like most other illnesses, eating disorders also have adverse effects on the person’s body. Eating disorders affect every organ system in the body. A study was carried out by Fotis Papadopoulos and his colleagues of more than 6000 individuals with Anorexia Nervosa over 30 years using Swedish registries. Overall, people with anorexia nervosa had a six-fold increase in mortality compared to the general population. Reasons for death included starvation, substance abuse, and suicide. The authors also found an increased rate of death from ‘natural’ causes, such as cancer. It is uncertain what the mortality rates are for individuals with other eating disorders, such as Bulimia Nervosa, or Other Specified or Unspecified Feeding or Eating Disorder, the latter of which is more common. Scott Crow and his colleagues conducted a longitudinal assessment of mortality over 8 to 25 years in 1,885 individuals with anorexia nervosa (N=177), bulimia nervosa (N=906), or eating disorder not otherwise specified (N=802) who presented for treatment at a specialized eating disorders clinic in an academic medical centre. Crude mortality rates for bulimia nervosa were 3.9%, 4.0% for anorexia nervosa and 5.2% for eating disorders not otherwise specified. The study concluded that individuals with eating disorders not otherwise specified, a form usually considered less severe, had elevated mortality rates. It also demonstrated that people diagnosed with eating disorders had an increased risk of suicide.

The effects of eating disorders on the gastrointestinal cavity:

  • Irritable Bowel Syndrome (IBS): Chronic condition that affects the large intestine. It is incredibly common in people diagnosed with eating disorders.

  • Gastroparesis: a condition that affects the motility of stomach muscles, preventing it from emptying properly.

  • Pancreatitis: can be caused by both malnutrition and purging.

  • Vomiting can cause the stomach to rupture and wear down the oesophagus.

  • When a person induces vomiting for a long period, the parotid salivary glands can get swollen. This can also happen when a person stops vomiting.

  • Binge-eating can cause the stomach to rupture.

  • Constipation: can have several causes

  1. Inadequate nutritional intake

  2. The use of laxatives over a long period can damage nerve endings and leave the body dependent on them to have a bowel movement.

  • Intestinal obstruction, perforation or infections.

  • Prolonged severe dehydration can lead to kidney failure.

The effects of eating disorders on the cardiovascular system:

  • Pulse and blood pressure begin to drop.

  • The risk of heart failure rises.

  • Reduced resting metabolic rate: a result of the body’s attempts to conserve energy.

  • Purging depletes the body of essential electrolytes. Electrolyte imbalances can lead to irregular heart rhythms and possible heart failure and/or death.

For example, the electrolyte potassium which is depleted by purging plays an important role in helping the heartbeat and muscles contract.

  • Malnutrition can decrease the body’s resistance to infection due to less production of white blood cells.

  • Anaemia develops when iron is deficient in the diet or too few red blood cells are being produced.

The effects of eating disorders on the nervous system:

  • While the brain weighs only 3 pounds, it consumes up to one-fifth of the body’s calories. Fasting, self-starvation, dieting and irregular eating means that the brain is not getting the nutrition it needs, causing the person to obsess over food and have difficulty concentrating.

  • To that end, the brain is composed of nearly 60% fat. Inadequate intake of fat can cause serious brain damage; brain lesions are sometimes seen in people diagnosed with anorexia nervosa.

  • The neurons have an insulating layer called myelin sheath, made of phospholipids, which help nerve impulses to travel and efficiently across nerve cells. Inadequate intake of fat can damage the myelin sheath, causing tingling in the hands, feet and extremities.

  • Extreme hunger or fullness after eating may make it difficult to fall asleep. People with anorexia nervosa also tend to have insomnia.

  • Neurons use electrolytes to send electrical impulses. Severe dehydration and electrolyte imbalances can cause muscle cramps and seizures.

  • People who are obese are more likely to have sleep apnea, a condition in which breathing repeatedly stops and starts while a person is asleep.

(a) (b)

(a) Shows an axial weighted Magnetic Resonance Image of the brain in an age and sex-matched healthy subject.

(b) Shows an axial weighted Magnetic Resonance Image of the brain of a 19 year-old woman with Anorexia Nervosa.

Image (b) shows enlargement of the lateral ventricles, sylvian fissures, and convexity sulci that is greater than expected at a patient at this age. The brain volume loss is shown to involve both cerebral grey matter and white matter.

The effects of eating disorders on the endocrine system:

  • Hormones are composed of amino acids and cholesterol. Without adequate uptake of fats and proteins, the level of secretion of sex hormones and thyroid hormones can fall.

  • Low levels of sex hormones can cause amenorrhea (a common effect of most eating disorders); it can cause menstruation to become irregular or stop completely.

  • Low levels of oestrogen, a sex hormone, can cause osteopenia or osteoporosis, increase the risk of broken bones and fractures.

  • Over time, binge-eating increases the chances that a person’s body will become resistant to insulin, and may thus lead to type 2 Diabetes.

Adaptations of the body:

  • Less fat consumption and low-calorie diets can cause dry skin and hair to become brittle and fall out.

  • During periods of starvation, to conserve heat, the body grows fine, downy hair called lanugo.

Eating disorders can take a heavy toll on the mind and body of individuals. Individuals suffering from them can seek help from a licensed practitioner, to possibly halt or even reverse the effects. Eating disorders can be cured, in the way that individuals fully recover and their behaviours do not reoccur. It is possible to have a healthy relationship with food, develop a positive body image, learn effective coping skills to deal with stress and anxiety, and move past the feelings, experiences, and fears contributing to the problem.



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