Abstract
Anorexia nervosa is a serious mental illness characterized by voluntary restriction of food intake and avoidance of high-calorie food. Anxiety, highly comorbid with anorexia nervosa, appears to be a significant, yet underexplored, factor affecting core behavioural symptoms such as food restriction and compulsive physical exercise. The aims of this review are to disentangle the influence of anxiety in food decision-making in anorexia nervosa and to offer a comprehensive model connecting the mechanisms involved. The shift from food approach to avoidance seems to be a conditioned response, underpinned by an activation of salience and fear circuitry. Altered neurotransmission (dopamine, serotonin) and neuroendocrine release (leptin, ghrelin, cortisol), aberrant neural structure activation (hyperactivation of the amygdala and hypoactivation of the insula-ventral striatum circuit) and cognitive and behavioural traits shared by anxiety and anorexia nervosa (rigidity, compulsiveness) contribute to these modifications. Animal models suggest a bidirectional relationship between food restriction and anorectic-like behaviours, strengthening yet complexifying the link between anxiety and food choice in anorexia nervosa. Therapeutic strategies focusing on anxiety and the conditioned response could contribute to restore healthy food choices and dissociate food stimuli from the anxious response elicited.