Rs = 0.985 p = 0.0001. When comparing the results of determining body fat by the Bland-Altman method, the average difference between the two methods was 0.6 ± 2.3 %, the degree of discrepancy was from -4 to + 5 %. The prevalence of obesity among dialysis patients by BMI was 29.4 % among women and 19.4 % among men. However, according to the results of both caliperometry and bioimpedance measurements, the real prevalence of obesity exceeded 90 %. CONCLUSION. Diagnosing obesity by BMI does not provide an indication of the true prevalence of obesity in dialysis patients. For this purpose, it is necessary to use bioimpedance or caliperometry. Both methods give comparable results and can be considered interchangeable.