Body mass index cut offs to define thinness in children and adolescents: international survey
Tim Cole, Katherine M. Flegal, Dasha Nicholls, Alan A. Jackson
BMJ
Abstract
OBJECTIVE: To determine cut offs to define thinness in children and adolescents, based on body mass index at age 18 years. DESIGN: International survey of six large nationally representative cross sectional studies on growth. SETTING: Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States. SUBJECTS: 97 876 males and 94 851 females from birth to 25 years. MAIN OUTCOME MEASURE: Body mass index (BMI, weight/height(2)). RESULTS: The World Health Organization defines grade 2 thinness in adults as BMI <17. This same cut off, applied to the six datasets at age 18 years, gave mean BMI close to a z score of -2 and 80% of the median. Thus it matches existing criteria for wasting in children based on weight for height. For each dataset, centile curves were drawn to pass t