3. Anorexia
Anorexia nervosa is an eating disorder characterized by food restriction, inappropriate
eating habits or rituals, obsession with having a thin figure, and an irrational fear of weight
gain. It is accompanied by a distorted body self-perception, and typically involves excessive
weight loss.
Due to their fear of gaining weight, individuals with this disorder restrict the amount of food
they consume. Outside of medical literature, the terms anorexia nervosa and anorexia are
often used interchangeably; however, anorexia is simply a medical term for lack of appetite
and the majority of individuals afflicted with anorexia nervosa do not, in fact, lose their
appetites.
Anorexia nervosa is often coupled with a distorted self image which may be maintained by
various cognitive biases that alter how the affected individual evaluates and thinks about
their body, food, and eating. People with anorexia nervosa often view themselves as
overweight or "big" even when they are already underweight. While the majority of people
with anorexia nervosa continue to feel hunger, they deny themselves all but very small
quantities of food.
Anorexia nervosa is diagnosed approximately nine times more often in females than in males.
In 2013 it resulted in about 600 deaths globally up from 400 deaths in 1990. It is a serious
health condition with a high incidence of comorbidity and similarly high mortality rate to
serious psychiatric disorders.
4. Bulimia
Bulimia nervosa is an eating disorder characterized by binge eating and purging, or
consuming a large amount of food in a short amount of time followed by an attempt to rid
oneself of the food consumed (purging), typically by vomiting, taking a laxative, diuretic,
or stimulant, and/or excessive exercise, because of an extensive concern for body
weight. Many individuals with bulimia nervosa also have an additional psychiatric
disorder. Common comorbidities are mood disorders, anxiety, impulse control, and
substance-misuse disorders. Patients with bulimia nervosa often have impulsive behaviors
involving overspending and sexual behaviors as well as having family histories of alcohol
and substance abuse, mood and eating disorders.
Some individuals may tend to alternate between bulimia nervosa and anorexia nervosa.
Bulimia is also commonly accompanied with fasting over an extended period of time.
These dangerous, habit-forming practices occur while the sufferer is trying to keep their
weight under a self-imposed threshold. It can lead to potassium loss and health
deterioration, with depressive symptoms that are often severe and lead to a high risk of
suicide . Bulimia nervosa is considered to be less life-threatening than anorexia; however,
the occurrence of bulimia nervosa is higher. Bulimia nervosa is nine times more likely to
occur in women than men. Up to 1% of women have bulimia nervosa.
5. Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it
may have a negative effect on health, leading to reduced life expectancy and/or increased
health problems.
Obesity increases the likelihood of various diseases, particularly heart disease, type 2
diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity is
most commonly caused by a combination of excessive food energy intake, lack of physical
activity, and genetic susceptibility, although a few cases are caused primarily by genes,
endocrine disorders, medications, or psychiatric illness. Evidence to support the view that
some obese people eat little yet gain weight due to a slow metabolism is limited. On average,
obese people have a greater energy expenditure than their thin counterparts due to the
energy required to maintain an increased body mass.
Dieting and exercising are the main treatments for obesity. Diet quality can be improved by
reducing the consumption of energy-dense foods, such as those high in fat and sugars, and
by increasing the intake of dietary fiber. With a suitable diet, anti-obesity drugs may be taken
to reduce appetite or decrease fat absorption. If diet, exercise, and medication are not
effective, a gastric balloon may assist with weight loss, or surgery may be performed to reduce
stomach volume and/or bowel length, leading to feeling full earlier and a reduced ability to
absorb nutrients from food.