According to our current knowledge, this study is the first clinical trial to evaluate the effects of 450 mg/day TB supplementation in combination with a low‐calorie diet on serum levels of HDL‐c subgroups, the HDL‐c2/HDL‐c3 ratio, and the gene expression of PPAR‐α and Sirt1 in subjects with MetS. Here, SIRT1 is linked to metabolic syndrome.