O2SFoodHlth: Eating Disorders

There are a number of eating disorders which affect people.

  • anorexia nervosa
  • bulimia nervosa
  • binge eating disorder (BED)
  • other eating disorders (ENDOS)
  • food fadism

Eating disorders

  • involve abnormal eating habits
  • eat too much or too little
  • causes mental and physical problems

Nervosa is only added to the term to indicate psychological factors are involved.

eating disorder prevalence in australia

1 Million Australians have an eating disorder costing Australia $70 billion a year. 1 male dies to every 3 females. In 2012, 1828 people died from an eating disorder which is higher than the national road toll for the same period.

Anorexia Nervosa affects people who

  • have a serious problem with body image
  • think they are overweight even though they are often underweight and emaciated.

Bulimia Nervosa is a related disorder to Anorexia Nervosa and sufferers

  • eat large meals then compensate with self induce vomiting, laxatives or enemas.
  • will alternate with fasting and/or excessive exercise.
  • can be a range of different weights – overweight, normal or underweight.

In Binge Eating disorders (BED) sufferers

  • consume very large meals and eat excessive food
  • do not use any compensatory mechanism
  • are generally overweight or obese.

Physiology of Eating

Three prongs to the physiology of Eating:

  • Appetite – a DESIRE for certain foods.
  • Hunger – the BODY wants to eat
  • Satiety – the feeling of being satisfied.

Eating patterns are signalled by the hypothalamus and pituitary gland in the brain. Damaging these areas will cause problems with eating.

Leptin is a hormone that fat and gastric cells secrete. It plays a key role in regulating the energy intake and expenditure including feelings of appetite, hunger, metabolic rate and so on. Mice that can’t produce leptin become quite obese. Giving Leptin injections, they lose weight.

leptin deficiency

Leptin plays an important role in insulin resistance and fat storage in the body. However, in humans its role is unclear. injecting Leptin in humans doesn’t make them lose weight.

Psychological Factors

Eating disorders can be affected by genetic and biological factors however these are minor and not clearly understood.

Psychological factors are much more important along with social and cultural factors. The cause of eating disorders is therefore multifactorial.

  • cultural
  • social
  • environment
  • peer-pressure
  • personality (perfectionist, OCD, neuroticism, attention seeking etc)
  • family influences (history of food disorders or body image problems)
  • drug and alcohol use and abuse.

Cultural and peer pressure are very strong factors when influencing eating disorders. Female body image has gone through cyclical changes through the centuries, so what is considered beautiful changes a great deal over time.

Media attention to female beauty can be a powerful mechanism. A 2008 study showed 74% of Australian adult women and 70% of adolescent girls were dissatisfied with their body image or wanted to lose weight. In 2010, studies showed that adolescent females who dieted severely are 20% more likely to develop food disorders.

To counter this, there is now a culture of fat-pride in society. Most males prefer a rubenesque female with pronounced curves which women deem overweight.


Women who have curves and fat in their body are quite fertile so males are biologically drawn to them. Fertility figurines from thousands of years ago are all obese shaped.

Very lean women often stop menstruating, lowering their fertility. Oestrogen levels (the woman’s sex hormones) are based on fats and cholesterol; if you have adequate fat, you are making adequate amounts of hormones and are therefore more fertile.

Bulimia Nervosa is a cycle of binge eating followed by purging. Purging can take any of the following forms:

  • Vomiting
  • Enemas
  • Laxatives
  • Diurectics

Binge Eating Disorder differs in that a large amount of food is ingests but the sufferer doesn’t register satiety and has no compensation mechanisms in place.

cognitive behaviour therapy

Cognitive Behaviour Therapy (CBT) can help along with medications. Wellbutrin is often used as it reduces hunger, is an antidepressant, reduces cravings for cigarettes and doesn’t affect sex drive. In Australia it is called Zyban.


EDNOS stands for Eating Disorder Not Otherwise Specified and includes a number of different eating disorders.

Compulsive Overeating Disorder CED has the following features

  • fantasies about food
  • tends to graze all day
  • enjoys food and the ritual of eating

Our culture encourages CED behaviour via cooking shows, food magazines, Man Vs Food etc)

PICA is the eating of non-food items and may include licking and chewing but not always swallowing. Factors likely to influence Pica

  • pregnancy
  • nutrient deficiency (e.g. iron)
  • autism
  • psychological factors

Pregorexia is seen in pregnant women who

  • have body image issues
  • overexercise and undereat
  • damage their baby

Drunkorexia is what lovers of alcohol may suffer from. Sufferers

  • don’t eat enough food
  • fill up on alcohol for their joules.

Orthorexia Nervosa affects nutritionally educated people. They normally

  • eat healthfully, eating only pure food
  • have their life ruled by eating well
  • don’t enjoy food or the act of eating

Food Fadism are people who jump from one fad diet to another. Examples of this are The Yellow Diet or the The Grapefruit Diet. Fad diets tend to be ones that choose one food group or colour, or ask you to eliminate certain food groups from your diet.


One thought on “O2SFoodHlth: Eating Disorders

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s