Many studies indicate that an anthocyanin-rich diet has beneficial effects preventing metabolic disease. In the present study, the molecular mechanism underlying the antiobesity effect of consuming blackberry anthocyanins (BLA) and blueberry anthocyanins (BBA) was investigated in high-fat-diet- (HFD-) fed C57BL/6 mice. Sixty mice were administered a low-fat diet (LFD), a HFD, or a HFD plus orlistat, and BLA or BBA in their daily food for 12 weeks. As a result, the consumption of BLA and BBA inhibited body weight gain by 40.5% and 55.4%, respectively, in HFD-fed mice. The BLA and BBA treatments markedly reduced serum and hepatic lipid levels and significantly increased hepatic superoxide dismutase and glutathione peroxidase activities. In addition, the treatments effectively increased fecal acetate and butyrate levels and significantly attenuated expression of tumor necrosis factor TNF-α, interleukin-6, and nuclear factor-kappaB genes. Moreover, gas chromatography time-of-flight mass spectroscopy results suggested that BLA and BBA significantly affected the hepatic lipid and glucose metabolic pathways, including glycerophospholipid metabolism, glutathione metabolism, and the insulin-signaling pathway. Therefore, BLA and BBA ameliorated diet-induced obesity by alleviating oxidative stress and inflammation and accelerating energy expenditure.