A 35-year-old female presents reporting episodes of eating unusually large quantities of food in discrete time periods, approximately 3 times per week for the past 5 months. During these episodes, she describes feeling unable to stop eating and consuming food much more rapidly than normal. She reports eating alone due to embarrassment, feeling disgusted with herself afterward, and marked distress about the episodes. She denies self-induced vomiting, laxative or diuretic use, fasting, or excessive exercise after episodes. Her BMI is 34. She expresses dissatisfaction with her body but does not describe her self-worth as being predominantly determined by weight or shape. Which diagnostic differentiation is most critical?