Eating disorder portion of the vulnerability to develop eating disorders can be inherited, and there is evidence to show that there is a genetic locus that shows susceptibility for developing anorexia nervosa. About 60% of eating disorder cases are attributable to biological and genetic components. Other cases are due to external reasons or developmental problems. There are also other neurobiological factors at play tied to emotional reactivity and impulsivity that could lead to binging and purging behaviors. Epigenetics: Epigenetic mechanisms are means by which environmental effects alter gene expression via methods such as DNA methylation; these are independent of and do not
Night eating syndrome Night eating syndrome Night eating syndrome (NES) is an eating disorder, characterized by a delayed circadian pattern of food intake. Although there is some degree of comorbidity with binge eating disorder, it differs from binge eating in that the amount of food consumed in the evening/night is not necessarily objectively large nor is a loss of control over food intake required. It was originally described by Dr. Albert Stunkard in 1955 and is currently included in the other specified feeding or eating disorder category of the DSM-5. Research diagnostic criteria have been proposed and include evening hyperphagia (consumption of 25%