Normal weight obesity in Korean adults.

ABSTRACT

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 20 years 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; 18·5-22·9 kg/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 20·6% and 33·4% BF, respectively, and the second cut-off values (defined as obesity) were 25·7% and 36·0% 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.