What Are Eating Disorders?
An eating disorder causes an individual to interact with food in an unhealthy way: eating excessive amounts in an uncontrolled manner, limiting food intake or getting rid of food through purging, fasting, laxative intake or over-exercising. It is also possible for a combination of these behaviours to occur together.
Individuals who have an eating disorder do not have a direct problem with food but rather in the feelings provoked when eating. They may become fixated with their weight or body image and use the intake of food as a way of coping with insecurities.
Eating disorders are increasing in young people on a global level. They can affect people of all ages; however, pre-teens, adolescents and young adults are particularly at risk. Eating disorders can affect all cultures, countries and gender identities.
The Diagnostic and Statistical Manual of Mental Disorders (DSM-5), outlines the criteria for diagnosis of an eating disorder.
Young people can reach the threshold for diagnosis in the following:
- Avoidant/Restrictive Food Intake Disorder (ARFID)
- Anorexia Nervosa (AN)
- Binge Eating Disorder (BED)
- Bulimia Nervosa (BN)
- Other specified Feeding and Eating Disorders
- Pica
- Rumination Disorder
- Unspecified Feeding and Eating Disorders.
Orthorexia is not formally listed in the DSM-5 (instead, patterns may be grouped under ARFID or AN).
Can Eating Disorders Be Predicted?
A new study, published online in JAMA Network Open (Dec 2020), suggests several factors present in early adolescence may help in predicting eating disorders, and could therefore create opportunities for earlier intervention and prevention.
The researchers identified a number of factors present in early adolescence differentially associated with future disordered eating behaviours (DEBs), in addition to symptoms of generalised anxiety and depression. These factors included:
- higher body mass index (BMI)
- neuroticism
- impulse control
- addiction-related behaviours.
Also, genetic analyses showed strong etiologic overlap between higher BMI, neuroticism, attention-deficit/hyperactivity disorder (ADHD) and disordered eating.
Sylvane Desrivieres, PhD, King’s College: London (and colleagues) analysed data from the IMAGEN population study that included longitudinal measures of the symptoms of eating disorders and various other psychiatric and psychological issues, in addition to genomics.
The findings are based on the assessments of 1,623 adolescents enlisted at a mean age of 14.5 years. These were then followed up at ages 16 and 19 years.
At any of the assessment time points, it was found that:
- 278 adolescents (17.1%) reported binge eating
- 334 adolescents (20.6%) reported purging
- 356 adolescents (21.9%) reported dieting.
Binge eating
Among the precursors of DEBs, the following were associated with future binge eating:
- conduct problems (OR, 1.41; 95% CI, 1.17 – 1.69)
- high levels of neuroticism (OR, 1.04; 95% CI, 1.01 – 1.06)
- deliberate self-harm (OR, 2.18; 95% CI, 1.37 – 3.45).
Purging
The following precursors were associated with later purging:
- conduct problems (odd ratio [OR], 1.42; 95% CI, 1.20 – 1.68)
- deliberate self-harm (OR, 2.59; 95% CI, 1.69 – 3.95)
- low levels of agreeableness (OR, 0.95; 95% CI, 0.92 – 0.97)
- drug abuse (OR, 2.91; 95% CI, 1.78 – 4.74)
- alcohol misuse (OR, 1.31; 95% CI, 1.10 – 1.54).
Dieting
Higher BMI in early adolescence was associated with future dieting (OR, 3.44; 95% CI, 2.09 – 5.65).
These observations mirrored the phenotypic findings on a genetic level.
A higher polygenic risk score (PRS) for BMI was associated with dieting, whereas the PRS for neuroticism and ADHD were associated with a higher risk for binge eating and purging, respectively.
Eating disorders and Other Mental Health Problems
The research also found that eating disorders often preceded other mental health problems.
Dieting at 14 years was associated with future symptoms of:
- generalised anxiety (OR, 2.27; 95% CI, 1.14 – 4.51)
- depression (OR, 2.53; 95% CI, 1.56 – 4.10)
- emotional problems (OR, 1.24; 95% CI, 1.08 – 1.43)
- self-harm (OR, 2.10; 95% CI, 1.51 – 4.24)
- smoking (OR, 2.16; 95% CI, 1.36 – 3.48).
Purging at 14 years was associated with the later development of symptoms for:
- anxiety (OR, 2.48; 95% CI, 1.49 – 4.12)
- depression (OR, 2.87; 95% CI, 1.69 – 5.01).
Clinical Implications For Eating Disorder Prevention Programs
The study also suggests ‘genetic predispositions and psychopathological mechanisms related to obesity, ADHD and personality are differentially associated with the vulnerability for eating disorders in adolescence. These results may have clinical implications for targeted ED prevention programs.’
Carol Kan, PhD, and Moritz Herle, PhD, King’s College: London, additionally note that the findings have important implications for clinical practice. They note:
‘Given the interwoven nature of both childhood psychiatric disorders, namely [ADHD] and adolescent affective disorders with eating disorder symptoms, greater clinical awareness and prompter recognition of psychiatric comorbidities by primary care teams are essential’.
‘Identifying individuals who are at risk of developing eating disorders will create opportunities for earlier intervention, potentially preventing the onset of eating disorders or improving their clinical course’.
Kan and Herle also comment that this can only be achieved with multidisciplinary efforts by clinicians in psychiatry and primary care, who need to work closely with the patient as well as the patient’s family and friends.
Failure to recognise and treat eating disorders can have ‘devastating consequences. Such failures contribute to the chronicity and severity of the illness as well as the development of comorbidities, such as anxiety and depression,’ Kan and Herle conclude.
JAMA Network Open. Published online, December 2, 2020. Full text, Commentary
