Eating Disorders

Question 1

Define anorexia nervosa

Answer 1

Eating disorder characterised by deliberate weight loss, an intense fear of fatness, distorted body image and endocrine disturbances

Question 2

Predisposing factors for anorexia nervosa

Answer 2

Biological
- genetic
- fhx
- female
- early menarche
Psychological
- sexual abuse
- preoccupation with slimness
- dieting behaviours starting in adolescence
- low self-esteem
- premorbid anxiety or depressive disorder
- perfectionism, obsessional/anankastic personality
Social
- western society - pressure to diet in a society that emphasises being thin
- bullying revolving around weight
- stressful life events

Question 3

Precipitating factors for anorexia nervosa

Answer 3

Biological
- adolescence and puberty
Psychological
- criticism regarding eating, body shape or weight
Social
- occupational or recreational pressure to be slim - ballet, models

Question 4

Perpetuating factors for anorexia nervosa

Answer 4

Biological
- starvation leads to neuroendocrine changes that perpetuate anorexia
Psychological
- perfectionism
Social
- occupation
- western society

Question 5

ICD-10 criteria for the diagnosis of anorexia nervosa

Answer 5

Fear of weight gain
Endocrine disturbances - amenorrhoea, loss of sexual interest and potency
Emaciated - abnormally low body weight < 17.5
Deliberate weight loss
Distorted body image
Present for at least 3 months and absence of
- recurrent episodes of binge eating
- preoccupation with eating/craving to eat

Question 6

Differential diagnosis of anorexia nervosa

Answer 6

Bulimia nervosa
Eating disorder not otherwise specified
Depression
OCD
Schizophrenia
Organic causes of low weight - diabetes, hyperthyroidism, malignancy
Alcohol or substance misuse

Question 7

Complications of anorexia nervosa

Answer 7

Metabolic
- hypokalaemia, hypercholesterolaemia, hypoglycaemia, impaired glucose tolerance, deranged LFTs, increased urea and creatinine, low potassium, low phosphate, low magnesium, low albumin, low chloride
Endocrine
- increased cortisol, increased growth hormone, reduced T3/4, reduced LH, FSH, oestrogen and progestogens leading to amenorrhoea, reduced testosterone
GI
- enlarged salivary glands, pancreatitis, constipation, peptic ulcers, hepatitis
CVS
- cardiac failure, ECG abnormalities, arrhythmias, reduced BP, bradycardia, peripheral oedema
Renal
- renal failure, renal stones
Neuro
- seizures, peripheral neuropathy, autonomic dysfunction
Haem
- iron deficiency anaemia, thrombocytopenia, leukopenia
MSK
- proximal myopathy, osteoporosis
Others
- hypothermia, dry skin, brittle nails, lanugo hair, infections, suicide

Question 8

Features of binge eating disorder

Answer 8

Recurrent episodes of binge eating without compensatory behaviour such as vomiting, fasting or excessive exercise

Question 9

Features of EDNOS or atypical eating disorder

Answer 9

Closely resembles other eating disorder but does not meet diagnostic criteria

Question 10

Management of anorexia nervosa

Answer 10

Aim for 0.5-1kg/ week weight gain for inpatient and 0.5kg/week outpatient
Biological
- treatment of medical complications
- SSRIs - for comorbid depression or OCD
Psychological
- psycho-education about nutrition
- CBT
- cognitive analytic therapy
- interpersonal psychotherapy
- family therapy
Social
- voluntary organisations
- self help groups

Question 11

Criteria for hospitalisation for anorexia nervosa

Answer 11

Medical
- BMI < 14
- severe electrolyte abnormalities
Psych
- suicidal ideation

Question 12

Features of refeeding syndrome

Answer 12

Potentially life-threatening syndrome that results from food intake after prolonged starvation or malnourishment due to changes in phosphate, magnesium and potassium
- occurs due to insulin surge

Question 13

Features of refeeding syndrome

Answer 13

Hypokalaemia
Hypomagnesaemia
Hypophosphatemia
Abnormal glucose metabolism
Cardiac failure

Question 14

Define bulimia nervosa

Answer 14

Eating disorder characterised by repeated episodes of uncontrolled binge eating followed by compensatory weight loss behaviours and overvalued ideas regarding body shape/weight

Question 15

Aetiology of bulimia nervosa

Answer 15

Sense of compulsion to eat
Binge eating
Fear of fatness
Compensatory weight loss behaviours

Question 16

Predisposing factors for bulimia nervosa

Answer 16

Biological
- female sex
- fhx
- early onset of puberty
- type 1 diabetes
- childhood obesity
Psychological
- physical or sexual abuse
- childhood bullying
- parental obesity
- pre-morbid mental health disorder
- preoccupation with slimness
- parents with high expectations
- low self-esteem
Social
- living in a developed country
- profession
- difficulty resolving conflicts

Question 17

Precipitating factors for bulimia nervosa

Answer 17

Biological
- early onset puberty/menarche
Psychological
- perceived pressure to be thing may come from culture
- criticism regarding body weight or shape
Social
- environmental stressors
- family dieting

Question 18

Perpetuating factors for bulimia nervosa

Answer 18

Biological
- co-morbid mental health problems
Psychological
- low self-esteem
- perfectionism
- obsessional personality
Social
- environmental stressors

Question 19

ICD-10 criteria for diagnosis of bulimia nervosa

Answer 19

Behaviours to prevent weight gain
- self-induced vomiting, alternating periods of starvation, drugs (laxatives, diuretics, appetite suppressants), excessive exercise
Preoccupation with eating
- sense of compulsion which leads to binging
Fear of fatness
- self-perception of being too fat
Overeating
- at least 2 episodes per week over a period of 3 months

Question 20

Subtypes of bulimia nervosa

Answer 20

Purging
- patient uses self-induced vomiting and other ways of expelling food from body
Non-purging
- patients use excessive exercise or fasting after binge

Question 21

Complications of repeated vomiting

Answer 21

CVS
- arrhythmias, mitral valve prolapse, peripheral oedema
GI
- mallory-weiss tears, increased salivary glands
Metabolic/Renal
- dehydration, hypokalaemia, renal stones, renal failure
Dental
- permanent erosion of dental enamel secondary to vomiting of gastric acid
Endocrine
- amenorrhea, irregular menses, hypoglycaemia, osteopenia
Derm
- Russel’s sign - calluses on back of hand due to abrasion against teeth
Pulmonary
- aspiration pneumonitis
Neuro
- cognitive impairment, peripheral neuropathy, seizures

Question 22

Management of bulimia nervosa

Answer 22

Biological
- trial of antidepressants - fluoxetine
- medical complications 
Psychological
- psychoeducation about nutrition
- CBT
- interpersonal psychotherapy
Social
- food dietary to monitor patterns
- techniques to avoid binging 
- small, regular meals
- self-help programmes