In this study, high-fat diet (HFD)-induced obesity in mouse model was used to evaluate the dietary effect of saponins from stems and leaves of Panax ginseng (SLG), and to explore its mechanism of action in producing anti-obesity effects. The results indicate that SLG showed significant anti-obesity effects in diet -induced obese mice, represented by decreased serum levels of free fatty acids (FFA), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL)-cholesterol, glucose, leptin and insulin, as well as a reduction in overall body and liver weight, epididymal adipose tissue weight, and food efficiency, and inhibition of abnormal increases in acyl carnitine levels normally caused by an HFD. Additionally, the down-regulated expression of PPAR gamma, FAS, CD36, FATP2 and up-regulated expression of CPT-1, UCP-2, PPAR alpha, HSL, and ATGL in liver tissue was induced by SLG. In addition, the SLG groups showed decreased PPAR gamma, aP2 and leptin mRNA levels and increased expression of PPAR alpha, PGC-1 alpha, UCP-1 and UCP-3 genes in adipose tissues, compared with the HFD group. In short, SLG may play a key role in producing anti obesity effects in mice fed an HFD, and its mechanism may be related to regulation of thermogenesis, lipogenesis and lipolysis. (C) 2017 Elsevier Ltd. All rights reserved.