Body Mass Index and Body Fat in Anorexia Nervosa

Anthropometry is considered one of the main methods of nutritional assessment in individuals with anorexia nervosa (AN). In this chapter, we will focus on body mass index (BMI) and total body fat (BF). We introduce the reliable and validated techniques for their assessment during underweight, weight gain and after complete weight restoration, and their changes during the course of the disease. The chapter also discusses the association/relationship between BMI and BF and the most important treatment clinical outcomes in this population: (i) relapse, remission, and/or recovery; (ii) reduction and normalization in bone mineral density (BMD); and (iii) amenorrhea, resumption of menstrual cycle, and reproductive function.