Eating disorders: an evolutionary psychoneuroimmunological approach
Rantala et al. (2019) here reviews the progress that has been made in the past few years in understanding the most effective treatment for eating disorders. Although several hypotheses have been proposed, only the intrasexual competition hypothesis is well backed up by evidence. According to the current data, treatments should be designed to reduce chronic stress, inflammation, stress responsivity, and gut dysbiosis that are said to trigger these eating disorders. The author suggests that the meta-problem today between mating motives and food rewards leads to chronic stress, and results in disordered eating through a vicious cycle involving dieting. While chronic stress upregulates the serotonergic system and causes dissatisfaction in anorexia nervosa patients, dieting reduces the serotonin levels and dysphoric mood. Strictly dieting therefore leads to spikes in cortisol concentrations and neuroinflammation, as part of the vicious serotonergic-homeostatic stress/starvation cycle. Moreover, the rise of eating disorders may be partially attributed to variation in gut microbiota and stress responsivity, which influence neuroinflammation and the serotonergic system. It was theorized that perhaps it would be more effective to treat biopsychosocial causes rather than manifest symptoms of these eating disorders.