Abstract Body mass index (BMI) fails to detect altered nutritional state in the presence of overweight or obesity, since malnutrition can be present and masked by the abnor- mal amount of fat mass. Measuring body cell mass (BCM) contents for the evaluation of muscle mass and protein tis- sue states is well accepted. The aim of the present study was to apply body cell mass index (BCMI) to monitor the mus- cular mass changes of male and female Olympic athletes, renal dialysis patients, and anorexia nervosa patients in comparison with healthy subjects. The BCMI values of male subjects from the healthy group and Olympic athletes groups, but not the renal dialysis group, were significantly higher (p<0.0001) than those of female subjects from the same groups. In addition, subjects with normal or high BMI values may be malnourished as highlighted by a low BCMI. We believe the BCMI is more sensitive than the BMI for studying the nutritional status of the individual. Key words Creatinine clearance • Body cell mass • Body mass index • Athletes • Anorexia nervosa Introduction In field studies, measurements of body composition have traditionally been restricted to simple measures such as weight adjusted for various height power indices for assessing adiposity. Body mass index (BMI), which is cal- culated as weight divided by height squared (kg/m 2 ), has been shown to be highly correlated with the amount of fat mass [1]. Thus, measuring BMI is a poor approach for the measurement of muscle mass, protein status or lean tis- sues. Moreover, BMI is of little diagnostic value, since higher BMI values may not necessarily reflect excess adi- posity. For example, certain athletes, like body builders and heavy-weight boxers, and pregnant women may have high BMI values, which may be wrongly interpreted as overweight or obesity. The body cell mass (BCM), which is the metabolically active component of fat-free mass, is the single best predic- tor of a subject’s nutritional status [2, 3]. The normal range of BCM is set at 40% of the ideal healthy body weight [4]. The body cell mass index (BCMI), which is calculated as BCM divided by height squared (kg/m 2 ) [5], has been shown to be more sensitive to changes in protein status and lean tissue compared to BMI. The muscle mass depletion in certain pathologic conditions can be best described by the loss of BCM (e.g. sarcopenia [6], anorexia nervosa [7, 8], and renal dialysis patients [9]). In addition to bioelectric impedance analysis [5, 8, 9] and total-body potassium-40 counting [6], BCM can be estimated using creatinine clear- ance (CCr) [9]. Creatinine is produced by muscle cells and therefore its daily rate of production and of subsequent uri- nary excretion are strictly related to the amount of body muscle mass [2]. It has been shown that CCr is significant- ly correlated with a subject’s height, but not weight, an observation which has been translated into sex-specific stan- dard tables predicting ideal CCr values for a subject on the basis of his/her height [10]. The objective of the present Acta Diabetol (2003) 40:S286–S289 DOI 10.1007/s00592-003-0088-9 © Springer-Verlag 2003 A. Talluri • R. Liedtke • E.I. Mohamed • C. Maiolo • R. Martinoli • A. De Lorenzo The application of body cell mass index for studying muscle mass changes in health and disease conditions A. Talluri () • R. Liedtke Akern Srl, Via Lisbona 32-34, I-50065 Pontassieve, Florence, Italy E-mail: akern@akern.com E.I. Mohamed • C. Maiolo • R. Martinoli • A. De Lorenzo Division of Human Nutrition, Faculty of Medicine and Surgery University of Tor Vergata, Rome, Italy E.I. Mohamed Department of Biophysics, Medical Research Institute University of Alexandria, Egypt A. De Lorenzo Casa di Cura Nova Salus Srl, Trasacco, L’Aquila, Italy