[Evaluation of accuracy of body mass index in diagnosing of obesity in relation to body fat percentage in female aged 55-84 years]. / Posouzení objektivity hodnocení výskytu obezity na základe bodymass indexu vzhledem k procentuálnímu zastoupení telesného tuku u zen ve veku 55-84 let.

BACKGROUND: Currently, body mass index (BMI) is frequently used for evaluation of obesity prevalence. This weight to height index does not reflect variability and changes in body composition components, and therefore, the BMI prevalence data may significantly differ from those based on the body fat percentage (%BFM). For the above reason, the primary aim of the study was to determine the prevalence of overweight and obesity according to %BFM and relate these data to BMI categories in women aged 55-84 years. METHODS AND RESULTS: 446 females with an average age of 65.8 ± 6.4 years participated in this study. Body composition was measured using InBody 720. Our results have shown high prevalence of overweight and obesity in the study sample. Number of obese subjects increased with increasing age. We found the highest prevalence of obesity in females over 80 years. Evaluation of obesity according to BMI seems to be accurate in women with BMI > 30 kg/m2. We found only 1% of nonobese subjects (evaluated according to %BFM) in this BMI category. In contrast, there was found a large number of subjects with obesity (evaluated according to %BFM) among women in 18.5 to 24.9 kg/m2 and 25.0 to 29.9 kg/m2 BMI categories. CONCLUSIONS: The results have shown that obesity may be diagnosed in women with lower BMI (i.e., < 30 kg/m2). For this reason we recommend to evaluate the prevalence of obesity primarily from BFM% in this age group.