Characteristics of body fat, body fat percentage and other body composition for Koreans from KNHANES IV

Abstract

Accurate measurement of fat mass has become increasingly important with the increasing incidence of obesity. We assessed fat and muscle mass of Koreans with the Korea National Health and Nutrition Examination Survey IV (KNHANES IV). We studied 10,456 subjects (aged 20 to 85 yr; 4,476 men, 5,980 women). Fat and muscle mass were measured by dual-energy x-ray absorptiometry. Reference values of body compositions were obtained using the LMS method. The fat mass index (FMI, body fat mass/height(2); kg/m(2)) of Korean men did not correlate with age (P = 0.452), but those of Korean women (P < 0.001) did. The ratio of percentage of fat in the trunk and legs was positively related with age in both the genders. The appendicular lean mass/height(2) (kg/m(2)) of Korean men was negatively related to age (P < 0.001). In women, this ratio increased with age (P < 0.001). When we defined obesity according to the FMI classification, the rates of obesity were 6.1% (FMI > 9 kg/m(2)) in men and 2.7% (FMI > 13 kg/m(2)) in women. It is concluded that the muscle mass decreases and obesity increases with aging in Korean men, whereas both fat mass and obesity increase with aging in Korean women.

Keywords: Body composition; DXA; Korea; NHANES; Obesity; Sarcopenia.

Fig. 1

Percentile curves; the mean, 3rd, 10th, 25th, 75th, 90th, and 97th percentiles superimposed on raw data values. BMI (kg/m²), waist circumference (cm), FMI (kg/m²), fat percentage (%), trunk/legs fat percentage ratio, trunk/limb fat mass ratio, appendicular lean mass/height², and appendicular/trunk lean mass ratio are considered. BMI, body mass index; FMI, fat mass index.

Fig. 2

Prevalence of overweightness and obesity in Korea, based on FMI as a function of age (A, men; B, women). FMI values are listed in Table 4. FMI, fat mass index.