9 - eating disorders I

Question 1

what is BMI?

Answer 1

body mass index
weight in kg/height in m2

overweight = BMI>25
obese = BMI>30

Question 2

what is the diagnostic criteria for anorexia nervosa?

Answer 2

1. persistent restriction of energy intake leading to significantly low body weight
2. intense fear of gaining weight OR persistent behaviour that interferes with weight gain
3. disturbance in the way one’s body weight or shape is experiences OR

undue influence of body shape and weight on self-evaluation OR

persistent lack of recognition of the seriousness of the current low body weight

Question 3

what are the subtypes of anorexia nervosa?

Answer 3

restricting
binge-eating/purging type

Question 4

critiques of anorexia nervosa diagnostic criteria

Answer 4

• people differ in their set point for weight (is weight/BMI useful)
• various suggestions over the years
• athletes are classed as overweight
• ballerina and gymnasts sanctioned to be underweight

Question 5

what makes us more likely to notice anorexia?

Answer 5

• better at spotting extreme examples
• when we have seen before and after states
• where weight loss is way beyond BMI 17.5

Question 6

what is the diagnostic criteria for bulimia nervosa?

Answer 6

1. recurrent episodes of binge eating:
   - eating, in a discrete period of time more than most people would eat
   - sense of lack of control over eating during episode
2. recurrent inappropriate compensatory behaviour in order to prevent weight gain:
   - self-induced vomiting, misuse of laxatives, diuretics, fasting, excessive exercise
3. binges and compensatory behaviours occur at lease once a week for 3 months
4. self-evaluation unduly influenced by body shape/weight

Question 7

critiques of bulimia nervosa diagnostic criteria

Answer 7

a binge can be:
- subjective (loss of control)
- objective (loss of control + excessive intake)

defining compensatory behaviours
- is vomiting always self-induced?
- is exercise for health or to control weight

how often do behaviours have to happen?

Question 8

what is the diagnostic criteria for binge-eating disorder?

Answer 8

1. recurrent episodes of binge eating:
   - eating, in a discrete period of time more than most people would eat
   - sense of lack of control over eating during episode
2. associated with 3 or more of the following:
   - eating rapidly
   - eating until uncomfortably full
   - eating lots of food when not hungry
   - eating alone because of embarrassment
3. marked distress regarding binge eating
4. binging at least once a week for 3 months

not associated with compensatory behaviours

Question 9

critiques of binge eating disorder diagnostic criteria

Answer 9

same issues as for bulimia nervosa

need to understand motivation for introducing this category
- access to insurance money to treat overweight/obese patients

BED patients have trouble accessing services

Question 10

what are other specified feeding and eating disorders (OSFED)?

Answer 10

• atypical cases
• present with many symptoms of other eating disorders but do not meet full criteria for diagnosis
• introduced for insurance reasons

Question 11

what are examples of OSFEDs?

Answer 11

• atypical anorexia (weight loss but still within normal range)
• atypical bulimia (of low frequency or limited duration)
• atypical binge-eating disorder (of low frequency or limited duration)
• purging disorder
• night eating syndrome

Question 11

what is avoidant/restrictive food intake disorder (ARFID)?

Answer 11

• primarily in children and young people
• disturbance in eating (weight loss, nutritional deficiency)
• absence of typical beliefs about food or fear of weight gain
• replacing and extending ‘fussy’ eating

Question 12

what are the subtypes of ARFID?

Answer 12

• sensory-based avoidance
• lack of interest
• food associated with fear-evoking stimuli

effective treatments are primarily behavioural, focusing on anxiety/exposure

Question 13

what did Fairborn et al say?

Answer 13

diagnosis of specific eating disorders does not do what it should
- 40-50% of cases don’t fit neatly into diagnoses
- OSFED are largest single group
- many fail to stay in one diagnosis
- does not indicate best treatment

we should shift away from rigid diagnoses to trans diagnostic model

Question 14

what are the biological risks associated with eating disorders?

Answer 14

• cardiac complications
• muscular weakness
• osteoperosis
• liver damage
• oesophageal tearing
• fainting

Question 15

what is incidence?

Answer 15

number of new cases in a set window of time

Question 16

what is prevalence?

Answer 16

number of current cases (point prevalence) or number of people who have had the problem over the past year (annual prevalence) or over lifetime (lifetime prevalence)

Question 17

why is it hard to calculate incidence?

Answer 17

slow onset
secrecy
slow diagnosis

Question 18

what is the lifetime prevalence rates of eating disorders?

Answer 18

anorexia = 4% women, 0.3% men
bulimia = 3% women, 1% men
binge eating disorder = 2.8% women, 1% men

indication that OSFED has highest lifetime prevalence

western cultures: prevalence of bing eating 6.1% women, 0.7% men

Question 19

why is it not enough to look at medical records?

Answer 19

• only say how many cases were spotted
• GPs not perfect at spotting cases

Question 20

what is the impact of westernisation on eating disorders?

Answer 20

increased identification and prevalence

Curacao study showed more cases among non-whites in recent years

Fiji study showed a clear link to the introduction of western media

Question 21

why is the causal evidence for eating disorders very weak?

Answer 21

• lack longitudinal data
• selective sampling
• risk of selecting memory and when asking
• risk of misinterpreting associations

Question 22

why are neurobiological factors for eating disorders unclear?

Answer 22

• where are responsible genes?
• are they responsible for eating disorders direction or other risk factors
• is hypothalamic damage preventing hunger?
• issue of causality

Question 23

what maintains an eating disorder?

Answer 23

cognitive patterns

Question 24

what are the two main cognitive patterns in eating disorders?

Answer 24

• broken cognitive link between eating and weight
• overvaluation of appearance and weight to be acceptable

Question 25

what is the ‘broken cognitive link’?

Answer 25

• drives restriction, then bingeing, then gaining weight, then restriction
• cognitive dissonance element

Question 26

what are safety behaviours?

Answer 26

behaviours that calm us temporarily when we are anxious but long-term makes them more fearful of overeating

• bing-eating
• restricting
• body avoidance/checking
• exercise
• purging

Question 27

what emotional factors of eating disorders?

Answer 27

• anxiety is the biggest single emotion maintaining and and triggering eating problems
• anger
• loneliness
• boredom
• depression is more of a consequence than a cause

Question 28

what are perceptual factors involved in eating disorders?

Answer 28

• think they are 25-30% larger than they are
• misperceive our weight ‘thought-shape fusion’, thinking about foot makes them larger

Question 29

what are social factors involved in eating disorders?

Answer 29

• social pressure to be thin is widespread in western culture
• evidence that reading fashion magazines worsens body image, self-esteem
• social media is more aggressive, image-based sites encouraging comparison, ‘thinspiration’

Question 30

how do we formulate behaviours of a an eating disorder?

Answer 30

used to normalise what patients do when they binge-eat
identify triggers and setting conditions
- exposure
- starvation
- emotion/stress
- disinhibition (alcohol etc)

Question 31

what is the model used to formulate cases?

Answer 31

A-B-C model
linking antecedents, behaviours and consequences

focus on feedback loops that maintain the problem