Constitutional thinness: unusual human phenotype of low bone quality

International audience; CONTEXT: Low fat mass and hormonal or nutritional deficiencies are often incriminated in bone loss related to thinness. Constitutional thinness has been described in young women with low body mass index (BMI) but close-to-normal body composition, physiological menstruation, no hormonal abnormalities, and no anorexia nervosa (AN) psychological profile.OBJECTIVE: Our objective was to determine whether constitutional thinness is associated with impaired bone quality.DESIGN, SETTING, AND PARTICIPANTS: This was an observational, cross-sectional study on 25 constitutionally thin and 44 AN young women with similar low BMI (