Extreme anorexia nervosa: medical findings, outcomes, and inferences from a retrospective cohort.

Extreme anorexia nervosa (AN) is defined as a BMI 3x upper limits of normal) predicted hypoglycemia, and low BMI predicted refeeding hypophosphatemia (p = .001). Although conclusions drawn from the findings presented in this descriptive study must be tempered by relevant clinical judgement, these findings showcase that patients with extreme AN are at significantly increased risk for many serious medical complications secondary to their state of malnutrition and also with initial refeeding.