Normal weight obesity in Korean adults

Background A better way to define obesity is in terms of the percentage of body fat (BF). Subjects with normal weight, but excess BF are vulnerable to cardiovascular diseases. Objective To evaluate the prevalence and characteristics of subjects having normal weight obesity (NWO) using optimal cut-offs of the BF percentage reflecting risk factors for cardiovascular disease (CVD) in Korean adults. Design and setting The Korea National Health and Nutrition Examination Survey in the Korean population conducted in 2009-2010. Participants We surveyed 5313 men and 6904 women aged 20years or older. Measurements We investigated the relations between the BF percentage (measured by dual-energy X-ray absorptiometry) and obesity-related risk factors for CVD (diabetes mellitus, hypertension and dyslipidaemia) in Korean adults. NWO was defined as the combination of a normal body mass index (BMI; 185-229kg/m(2) in Asian subjects) and BF percentages above the determined cut-off values. Results There were strong and graded associations of increasing BF percentages with the prevalence of CVD risk factors. The first cut-off values (defined as being overweight) in men and women were 206% and 334% BF, respectively, and the second cut-off values (defined as obesity) were 257% and 360% BF. Thirty-two per cent of normal weight adults had BF percentages greater than or equal to the overweight or obesity cut-offs (NWO). Subjects with NWO had a lower appendicular skeletal muscle mass, a more atherogenic lipid profile and greater insulin resistance. Conclusions Obesity can be defined as 26% BF or greater in Korean men and 36% BF or greater in Korean women. There was a high prevalence of clustering of cardiometabolic abnormalities among subjects with NWO.