Eating disorders are not a choice; they are serious biologically-influenced illnesses.
When first confronted with an eating disorder, we often see some of the same behaviours: restriction, binging, purging, and obsessive exercise. These are things we are all capable of and potentially do from time to time, so it seems like a choice to engage in these things, but biology plays a large role in the perpetuation of eating disorder behaviours.
The evidence
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Disordered eating behaviours can be driven by unconscious events.
Eating disorders are associated with changes in neurobiological pathways related to reward and self-control. The response to palatable foods, to reward and to punishment are guided by processes within the brain and are altered in those with eating disorders.
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Fundamental personality traits and cognitive styles are associated with eating disorders.
There have been consistent associations over many years of personality traits associated with eating disorders. These personality traits pre-date the eating disorder, get worse with acute illness and persist after recovery. These traits are influenced by genetics and are heritable. Common personality traits include harm avoidance, high or low novelty seeking behaviours, perfectionism, and inflexibility.
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Individuals with eating disorders seem to experience atypical responses to eating and activity.
Most of us get tired and irritable if we go without eating for a while, or struggle to get motivated to start that new gym routine. Many studies have shown that individuals with anorexia feel mood improvement with a negative energy balance (restriction) such that it feels calming and is anxiolytic. The responses to exercise and purging are also commonly atypical as well.
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Brain structure and function differ between those with active eating disorders and those without.
Structural neuroimaging has shown a reduction in grey matter in those with eating disorders, most pronounced in those with anorexia nervosa. Altered functioning in the limbic system has been widely demonstrated in those with binge eating disorder, bulimia nervosa and anorexia nervosa. There is also evidence of dysregulation in neurotransmitters in eating disorders, both dopaminergic and serotonergic systems.
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Feeding and activity behaviour is regulated biologically in animals.
For more references, see “The Science Behind the Nine Truths”.
Thank you to F.E.A.S.T. volunteers for compiling these resources for us: B.E., L.H. Photo credits J. Clarke.