9 - eating disorders I Flashcards
what is BMI?
body mass index
weight in kg/height in m2
overweight = BMI>25
obese = BMI>30
what is the diagnostic criteria for anorexia nervosa?
- persistent restriction of energy intake leading to significantly low body weight
- intense fear of gaining weight OR persistent behaviour that interferes with weight gain
- 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
what are the subtypes of anorexia nervosa?
restricting
binge-eating/purging type
critiques of anorexia nervosa diagnostic criteria
- 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
what makes us more likely to notice anorexia?
- better at spotting extreme examples
- when we have seen before and after states
- where weight loss is way beyond BMI 17.5
what is the diagnostic criteria for bulimia nervosa?
- 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 - recurrent inappropriate compensatory behaviour in order to prevent weight gain:
- self-induced vomiting, misuse of laxatives, diuretics, fasting, excessive exercise - binges and compensatory behaviours occur at lease once a week for 3 months
- self-evaluation unduly influenced by body shape/weight
critiques of bulimia nervosa diagnostic criteria
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?
what is the diagnostic criteria for binge-eating disorder?
- 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 - 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 - marked distress regarding binge eating
- binging at least once a week for 3 months
not associated with compensatory behaviours
critiques of binge eating disorder diagnostic criteria
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
what are other specified feeding and eating disorders (OSFED)?
- atypical cases
- present with many symptoms of other eating disorders but do not meet full criteria for diagnosis
- introduced for insurance reasons
what are examples of OSFEDs?
- 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
what is avoidant/restrictive food intake disorder (ARFID)?
- 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
what are the subtypes of ARFID?
- sensory-based avoidance
- lack of interest
- food associated with fear-evoking stimuli
effective treatments are primarily behavioural, focusing on anxiety/exposure
what did Fairborn et al say?
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
what are the biological risks associated with eating disorders?
- cardiac complications
- muscular weakness
- osteoperosis
- liver damage
- oesophageal tearing
- fainting
what is incidence?
number of new cases in a set window of time
what is prevalence?
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)
why is it hard to calculate incidence?
slow onset
secrecy
slow diagnosis
what is the lifetime prevalence rates of eating disorders?
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
why is it not enough to look at medical records?
- only say how many cases were spotted
- GPs not perfect at spotting cases
what is the impact of westernisation on eating disorders?
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
why is the causal evidence for eating disorders very weak?
- lack longitudinal data
- selective sampling
- risk of selecting memory and when asking
- risk of misinterpreting associations
why are neurobiological factors for eating disorders unclear?
- where are responsible genes?
- are they responsible for eating disorders direction or other risk factors
- is hypothalamic damage preventing hunger?
- issue of causality
what maintains an eating disorder?
cognitive patterns
