Optimal body fat percentage cut-offs for obesity in Chinese adults.

Obesity results in an increased risk of metabolic syndrome (MetS) and Type 2 diabetes (T2DM). Body fat percentage (BF%) is a common index of body composition. The aim of the present study was to determine the optimal BF% cut-offs for obesity to predict MetS and T2DM in Chinese adults. The baseline study group comprised 3916 Chinese adults (age 30-70 years of age); 2033 subjects without MetS or T2DM were followed up for a maximum of 5.5 years. The BF% was estimated using bioelectrical impedance analysis. Optimal BF% cut-offs were analysed by receiver operating characteristic (ROC) curves. Binary logistic regression analysis was performed to measure the association between obesity at baseline defined by BF% and newly developed MetS and T2DM. Mean BF% levels were lower in men than in women (23.9 ± 6.1% vs 33.5 ± 7.1%, respectively; P < 0.01). For men, the optimal BF% cut-offs for the prediction of MetS and T2DM were 25.45% and 26.65%, respectively; for women, the corresponding values were 34.95% and 36.55%. Subjects with high BF% (≥ 25% in men; ≥ 35% in women) had higher risks of incident MetS or T2DM than those with low BF% (< 25% in men; < 35% in women). The relative risks were 3.43 (95% confidence intervals (CI) 2.59-4.54) and 2.92 (95% CI 1.85-4.60), respectively. The optimal BF% cut-offs for obesity for the prediction of MetS and T2DM in Chinese men and women were around 25% and 35%, respectively.