Eating Disorders

Question 1

Characteristics of Anorexia Nervosa

Answer 1

• Excessive fear of gaining weight
• Body weight below normal (<85%)
• Amenorrhea (cessation of menstruation)
• Disturbed body image
• May involve
• • restricted intake
• • purging
• • Excessive exercise

Question 2

Characteristics of Bulimia Nervosa

Answer 2

Binge eating

• eating in a discrete period an unusual amount of food
• a sense of lack of control over eating during episode
• usual negative affect after binge Followed by weight compensatory behaviour - purging - diuretics

Time frame - at least 1x p/wk for 3 months

Self-evaluation strongly influenced by shape

Question 3

Characteristics of Binge-eating disorder

Answer 3

o Binge eating

o No (or little) compensation

o Usually put on weight

o At least 1x/week for 3 months

Question 4

Prevalence of Eating Disorders

Answer 4

o Relatively infrequent but severe

o Data hard to collect – need high risk samples, covering both adolescence & adulthood

o Overall prevalence – around 2-3% total eating disorders

o Anorexia less common – 0.5% lifetime

o Bulimia – 1.3% lifetime

Question 5

Sex distribution

Answer 5

o Primarily female disorders

o Overall 6-8 times more females than males with eating disorders

o Anorexia most dramatic – 95% female

o Male “equivalents”??

 Body builders, runners

Question 6

Onset

Answer 6

o Tend to occur early – disorders of adolescence/early adulthood

o Most cases begin during 10-20

o Anorexia – mean – 16 yrs. Almost no cases after mid 20’s

o Bulimia – mean – 18yrs, first cases a little earlier, but a few initial cases seen into middle age

o BED similar to BN

Question 7

Course

Answer 7

o Discrepancy between lifetime and point prevalence – suggests temporary disorders

o Binge disorders often short-lived or episodic

o Anorexia longer – several years

o Long-tern data – 75%+ of women no longer have disorder after a decade or so – but often still show symptoms

Question 8

Common co-morbidity

Answer 8

o Mood disorders

o Anxiety disorders

 OCD

 Social Phobia

o Substance Use

o Personality Disorders

 OCPD

 Borderline PD Narrated

o Higher risk for a lot of mental illnesses then the general population

o Higher risk with bulimia than anorexia for anxiety disorder, mood disorder, substance abuse disorder up to 9x.

 Anorexia still about 2x more likely than general pop for some but also evidence that anorexia is more of a unitary disorder.

Question 9

Medical complications

Answer 9

o Often severe complications – up to 3% with anorexia will die from complications, less from bulimia

o Menstrual irregularity (BN, cessation (AN)

o Cardiac arrhythmias and damge

o Complications from low weight (starvation)

 Low body temperature

 Low blood pressure and HR

 Lanugo growth • This layer of hair covering body

 Osteoporosis

o Complications from weight shifts and purging (BN)

 Receding gums, tooth decay, and loss

 Gastrointestinal disorders (e.g. IBS, Crohn’s disease)

 Kidney disease

 Internal damage and bleeding

Question 10

Mortality in hospitalised with eating disorders – Rosling et al., 2011

Answer 10

o 10% of those hospitalised had died after 10yrs

o BMI > 17.5 – 4x than gen pop

o BMI < 10.5 – 44x

Question 11

Heritability in eating disorders

Answer 11

o Strong familial component

 Increased risk in relatives – 4x for BN & 11x for AN

o Twin studies suggest around 50% variance

 Large study of AN heritability .48 - .76 depending on definition

 Similar variation for BN - .28 - .88

o Heritability shows overlap with depression and anxiety

o Concordance for MZ higher than concordance for DZ showing clear genetic links.

Question 12

Brain regions o Three components to explain in biology of eating – Treasure, 2010

Answer 12

 Homeostatic system involved in regulation of weight and hunger. Involves lower order brain areas

 Drive systems involved in triggers and motivations to eat/or restrict weight and include links with memory and learning.

 Higher order mental processes involved in meaning of weight and conscious control over energy

Question 13

Brain regions o Homeostatic system

Answer 13

 Major input from hypothalamus. Involved in several basic functions including hunger and eating

 Regulates body’s set point

 Damage to lateral hypothalamus leads rats to restrict eating

 Damage to ventromedial hypothalamus leads rats to continue eating and not to stop (often till death)

Question 14

Brain regions o Cause or effect

Answer 14

 Brain is markedly affected by low weight and starvation

 Structural differences very likely to be a result of starvation or prolonged dieting

 Difficult to determine whether these differences precede the disorder due to early onset and low prevalence

Question 15

Biochemical factors o Kaye et al. (2009) argue that biochemical processes may fall into two groups

Answer 15

 Those associated with traits that precede the disorder (causal)

 Those caused by dieting that might maintain the disorder (maintaining)

 Trait risk factors are general to many disorders (e.g. neuroticism)

 Therefore, most eating disorder research has focussed on the latter

Question 16

Biochemical factors o Serotonin

Answer 16

 Many studies have shown abnormalities in 5HT function in people with AN.

 Evidence that 5HT is involved in satiety and also impulse control and mood

 Reduced levels of 5HIAA in cerebro-spinal fluid (CSF)

 Complex relationship - increased binding of 5HT1A and reduced binding of 5HT2A receptors. Still found after recovery.

Question 17

Biochemical factors o Dopamine

Answer 17

 DA thought to be involved in reward learning and sensation-seeking c.f. substance abuse and also excessive exercise and impulsivity in some eating disorders

 Low levels of DA metabolites in CSF

 Polymorphism of DRD2 gene (control of DA D2 receptor) in anorexia

 Some evidence for increased D2 & D3 receptor binding in ventral striatum in AN.

Question 18

Narrated Transmitter metabolites Receptor binding

Answer 18

• Transmitter metabolites

o Studies show higher levels of serotonin and DA in recovered AN patients relative to controls

• Receptor binding

o Recovered AN patients had abnormal levels of 5HT2A binding at various at parts of the brain compared to controls and these appear to be independent of the effects of starvation.

Question 19

Psychological risk factors for eating disorders symptoms in females

Answer 19

o Body image dissatisfaction

 Strong concern over body weight and shape characterises all eating disorders

 Excessive importance placed on weight (e.g. weight as central to self esteem

 Includes perceptual/cognitive distortions (e.g. perceiving self as overweight

o Over concern with weight and shape

o Perfectionism

o General negative affectivity

o Low self esteem

o Early menarche

Question 20

Affective factors

Answer 20

o Involvement of depression, anxiety and obsession

o Importance of sense of order and control

o Low self-esteem and tendency to equate body size with self-worth

o Fear of weight gain

Question 21

Personality factors

Answer 21

o Internalisation of thin ideal

o Negative affectivity one of the key predictors

o Perfectionism

 Restriction and control

o Impulsivity

 Binging, purging

Question 22

Family factors

Answer 22

o Not a main cause, but likely to play some role in onset and maintenance

o As in most disorders, evidence is mixed and effects are small

o Nonspecific factors such as parent criticism and over protection – Criticism and focus on weight may be more specific

Question 23

Perception of body shape in eating disorders Eye gaze to body areas

Answer 23

o Tendency for controls to underestimate weight, eating disorders and obese to overweight

o 80% of controls to be accurate

o More overestimating and underestimating by eating disorder groups, less accurate

o Tovee et al

 Found results that their estimates were accurate.

 Greater discrepancy (5 BMI points) between BN estimates and ideals whereas AN were accurate and close to ideal. i.e. they want to be that thin.

Eye gaze

o Controls fairly equal share across body

o AN focussed more on fatty areas.

Question 24

Social attitudes to thinness

Answer 24

o Change in conception of attractiveness on Western society

o 1960’s Twiggy – reflection of move to thinner ideals of beauty

o Coincides with apparent increase in eating disorders

Question 25

Cultural influences on eating disorders

Answer 25

o Suggestion that eating disorders may be “culture-bound”

o Some evidence that AN not seen in some societies until recently – mixed evidence

o More evidence for culture restriction in BN - appears more common in West

o Possible increases in eating disorders with stronger Western influence

Question 26

Socio-economic status

Answer 26

o Some suggestion that eating disorders are more common among more affluent

o Stronger drive for thinness among more affluent

Question 27

Popular media and eating disorders

Answer 27

o Common tendency to “blame” media

o Many popular examples of super-thin models, pressure to be thin, negative connotations of overweight, etc

o Lots of anecdotal and circumstantial evidence

o But correlation is not causation

Question 28

Does the media “cause” eating disorders

Answer 28

o Theory – exposure to thin ideal -> body dissatisfaction -> eating disorder

o Several longitudinal studies provide some support

o Experimental studies – exposure to thin media images produces greater dissatisfaction and negative affect

Question 29

Average weight of playboy centrefolds

Answer 29

o From 90kg in 1960 to 86.5kg in 66, then to 84kg in 78.

Question 30

Lifetime risk for bulimia in females

Answer 30

o Risk spikes for those born after 1960+

o Methodological shortcomings in study.

Question 31

Eating disordered behaviour following introduction of TV in Fiji

Answer 31

o Traditional Fiji culture promotes eating to build a robust figure

o Looked at 63 adolescent girls in 95 (pre-TV) and 65 girls in 98

o BMI stayed the same

o Bingeing decreased

o Disordered eating behaviours doubled

o Vomiting to control weight from 0-11.3%

Question 32

Prediction of weight control from magazine reading

Answer 32

o Chance of weight control behaviours doubles by simply by having read weight control related magazines. Triples once you get to those who read often. Similar but weaker results with bingeing behaviour

Question 33

Body dissatisfaction in young girls after exposure to barbie

Answer 33

o Girls shown pictures of barbie, emme (plus sized model (16) who has a doll and control (animals)

o Body dissatisfaction lower for those who played with barbie and higher for those who played with emme. By 8 (year 3), effect is lost because girls find the dolls childish.

Question 34

Exposure to magazine models on body satisfaction in women high and low self esteem

Answer 34

o Teenage girls 14-18.

o Girls shown pictures of thin size models, average size women or control (fonts/colours)

o Divided girls into high self-esteem vs. low self-esteem

o Then measured perceived vs. ideal body size.

o Those with low self-esteem had a greater body dissatisfaction, girls with high SE may be positively affected and motivated.

Question 35

Classification of eating disorders

Question 36

risk factors for eating disorders - textbook

Answer 36

being overweight

high social class

acculturation to the majority

Question 37

ethnic differences in the US

Answer 37

white males prefer thinner women than african american males and this may contribuite to lower rates of eating disorders amongst AA women.

Question 38

those who diet are in fact at a greater risk of

Answer 38

bingeing

Question 39

interesting finding of the study on dietary restraint during WWII

Answer 39

the male subjects became obessed with food and eating.

this is also seen in AN patients becoming chefs for family and hoarding food.

may be a result of dieting or starvation alone