About eating disorders

• People experiencing some eating disorders may hold an inaccurate perception of their body size and shape, and attempt to control their weight and appearance through excessive dieting, exercising, and/or purging.¹²
• Personality traits of perfectionism and fear of failure, low self-esteem, and emotion avoidance are common among those living with anorexia nervosa.¹³ People living with anorexia nervosa often adhere to intense exercise routines.^{14, 15}
• Accompanied by a sense of loss of control, bulimia nervosa binges are often followed by feelings of guilt and shame. Binges are often counteracted by self-induced vomiting, fasting, over-exercising and/or misuse of laxatives, enemas, or diuretics.⁹ Eating disorders occur at any body size.¹⁶ People with bulimia nervosa may be slightly underweight, of average, or overweight status.¹⁷
• Feelings of guilt, disgust and depression often follow a binge-eating episode.^{5, 18} Unlike bulimia nervosa, binge-eating disorder does not involve purging. However, the illness can involve sporadic fasting and repetitive diets, as well as weight gain.¹⁹

• The lifetime prevalence of eating disorders in New Zealand is estimated to be between 1.5 and 2.1 per cent.¹² Eating disorders most commonly affect those aged between 25 and 44, but can strike at any age.²⁰ Eating disorders can affect anyone, from any gender, or cultural background.²⁰
• Like women, men experience disturbances in body image, binge eating and maladaptive weight/shape control behaviours.²¹ Importantly, eating disorders among men are significantly under-diagnosed.²² Indeed, the prevalence of binge-eating disorder may be nearly as high in men as in women, and the prevalence of extreme weight control behaviours, such as extreme dietary restrictions and purging, may be increasing more rapidly in men than women.²¹
  Some research suggests those who identify as lesbian, gay, bisexual, transgender or gender diverse may be at increased risk of developing eating disorders.^{23, 24}
• Māori and Pacific people constitute approximately 17 per cent and eight percent of New Zealand’s population respectively.^{25, 26} Data suggests that eating disorders are at least as common among Māori and Pacific populations as the remainder of the population.²⁰ Māori and Pacific populations though, are less likely to have contact with health services for mental health reasons, suggesting barriers to access.¹²
• For New Zealanders, the lifetime prevalence of anorexia nervosa is estimated to be 0.6 per cent, representing nearly 30,000 people.²⁷ The prevalence of New Zealanders who have had bulimia nervosa at any stage during their lives is estimated to be 1.3 per cent – equating to more than 62,000 people.¹² Almost two (1.9) per cent of New Zealand adults are expected to develop binge-eating disorder during their lifetime.¹⁹

Eating disorders cause significant distress and that impacts on the lives of the individual, their family, carers, partners and friends.²⁸ Medical complications of eating disorders include cognitive impairment, heart complications, growth retardation and osteoporosis.⁴

Young people with anorexia nervosa aged between 15 and 24 years have 10 times the age-adjusted mortality rate, compared to their same-aged peers, due to medical complications and suicide.^{12,29, 30}

Across eating disorders, psychotherapeutic interventions are the most effective and recommended first-line treatment.³¹

Multidisciplinary team treatment of eating disorders is the standard of care, with close coordination of medical, nutritional, and psychiatric treatments. Services range from intensive medical and psychiatric inpatient programs to residential, partial hospital, day treatment, and varying levels of outpatient care, which may entail general medical treatment, nutritional consultation and counselling, and individual, group, and family psychotherapy.³¹

Level of care should be determined according to a patient's overall physical status, including body mass index and medical stability, as well as psychological symptoms and social circumstances.

Hospital-level care is necessary in the context of serious medical complications or seriously impaired psychological function. It may also be necessary when there is a rapid or persistent decline in intake or weight, an inadequate response to lower levels of care, or when psychosocial or comorbidities interfere with effective outpatient management.³¹

There is not a standalone, distinct cause of eating disorders but rather a complex interplay among various risk factors that triggers its inception.³² Some of the factors that influence eating disorders include genetics, developmental challenges (including puberty), thinking styles (such as perfectionism), body dissatisfaction (body image has ranked among the top four concerns for young people over the past nine years³³) and socio-cultural pressures.³⁴

Twin and adoption studies highlight that genetics substantially contribute to the risk for developing eating disorders. There is a moderate-to-high heritability of anorexia nervosa, bulimia nervosa, and binge-eating disorder in females and males during adolescence and adulthood.³²

Data suggests that psychological and environmental factors interact with and influence the expression of genetic risk to cause eating disorders.³²

Sociocultural influences (i.e. media exposure, perceived pressures for thinness, thin-ideal internalisation, thinness expectancies) are risk factors for eating disorders, but not universally – only a subset of females and males are vulnerable to these influences.³²

Personality traits have received significant attention as a contributing cause of eating disorders. Negative emotionality/neuroticism, perfectionism, and impulsivity/negative urgency personality traits have all been shown to share a causative link to eating disorders.³²