Eating disorders 1 Flashcards
Underweight cases
Only 15% of eating disorder cases are underweight
Weight
Body mass index= wight in kg/(height in m)2
For most people it will be in the range of 19-25
Not biologically determined
Varies
BMI is not useful for younger people- use expected wight for heigh, adjust with age
if you’re <85% you are classed as underweight, if <70% you are classed as dangerously underweight
BMI over 25- overweight
BMI over 30- obese
Anorexia nervosa
Persistent restriction of energy intake leading to significantly low body weight
In context of what is minimally expected for age, sex, developmental trajectory, and physical health.
To be diagnosed this need to be combined with either:
- An intense fear of gaining weight or becoming fat
OR
- Persistent behaviour that interferes with weight gain
Disturbance in the way one’s body weight or shape is experienced
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
Evaluation
People differ in their se point for weight- so weight/BMI may not be any use
Bulimia nervosa
Recurrent episodes of binge eating
Eating in a discrete period of time more than most people would eat during a similar period and under similar circumstances
A sense of lack of control over eating during the episode
Recurrent inappropriate compensatory behaviour in order to prevent weight gain- self-induced vomiting, misuse off laxatives, fasting, excessive exercise
Diagnosis- binges an compensatory behaviour both occur at least once a week for three months
Self evaluation unduly influenced by weight/body shape
Does not occur exclusively during episodes of anorexia nervosa
Binge-eating disorder
Recurrent episodes of binge eating, a sense of lack of control
Eating much more rapidly than normal
Eating until feeling uncomfortable full
Eating large amounts of food when not feeling physically hungry
Eating alone because of feeling embarrassed by how much one is eating
Marked distress regarding binge eating
Bingeing for at least once a week for 3 months
In the US people need to meet the diagnostic criteria in order to get treatment through their insurance
Other specified feeding and eating disorders (OFSED)
Present many of the symptoms of other eating disorders, but do not meet the full criteria for diagnosis
Atypical anorexia nervosa- despite significant wight loss, the individual’s weight is within or above the normal range
Atypical bulimia nervosa- low frequency and or limited duration
Same with atypical binge-eating disorder
Purging disorder- make yourself sick without binging before
Night eating syndrome- eating while asleep/not fully conscious- don’t remember doing it
ARFID- avoidant/restrictive food intake disorder
Mainly seen in young people and children
Disturbance in eating or feeding
- Substantial weight loss/lack of weight gain
- Nutritional deficiency
- Dependence on supplements
No fear of food or weight gain
Used to b called ‘selective’ or ‘fussing eating’
Three subtypes:
Sensory-based avoidance- based on smell, texture, colour, presentation
Lack of interest
Food associated with fear evoking stimuli- developed through a learned history e.g. chocking on something
Treatment focuses bhaviour- tackling anxiety around food
Evaluation
40-50% of cases do not fit neatly into diagnoses
Atypical cases (OFSED) are the largest single group
Many fail to stay in one diagnosis
Does not indicate the best treatment
There is a sift away from rigid diagnoses- transdiagnostic model
Comorbid- a lot of people have other problems along with EDs
Anxiety disorder- OCD, social anxiety
Depression
Personality disorder
Alcohol use and substance use
Risks
Cardiac problems
Muscular weakness (cardiac failure)
Osteoporosis
Liver damage
Oesophegeal tearing
Fainting
Incidence and prevalence
Incidence- number of new cases in a set window of time
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)
Slow onset + secrecy + slow diagnosis = hard to calculate incidence
Prevalence rates
Anorexia nervosa- 4% of women, 0.3% of men
Bulimia nervosa- 3% of women, 1% of men
Binge eating disorder- 2.8% of women, 1% of men
When half the island of Fiji got satellite TV- they saw an increase in cases in this half. Could be because of body image issues presented by TV and social media
Causes
Early parenting, abuse, bullying, emotional invalidation, childhood obesity, parental mood/eating, puberty.
However the evidence for this is weak
- lack longitudinal data
- selective sampling- don’t ask people without an ED- no one to compare to
- risk of misinterpreting associations
Neurobiological factors
Monozygotic twins have the highest concordance rate
Are the genes identified predicting eating disorders or other related risk factors like perfectionism, low self esteem
Maintenance- cognitive patterns
Low-self esteem
Negative self attribution
Perfectionism
Broken cognitive link
People without an ED are aware that if they eat a lot they will gain weight, but it is in proportion. People with an ED think that even if they just eat a small amount of food their weight will go out of control.
A lot of cognitive dissonance- the discomfort a person feels when their behaviour does not align with their beliefs
Overvaluation
Overvaluation of appearance and weight as defining ourselves as being acceptable people
Safety behaviours
Behaviours that calm us temporarily when we are anxious, such as:
Binge eating
Restricting
Body avoidance/checking
Exercise
Purging
In the short term this makes us feel better and in control
This forms a vicious cycle
Emotional factors
Anxiety is the biggest maintaining and triggering emotion for eating problems
Perceptual factors
individuals with an eating disorder see themselves as 25-30% larger than they are.
Could be evidence of a temporal lobe problem?
No because the same applies to non-clinical women 10-15% overestimate
