Oligomeric polyphenol-enriched specified kiwifruit extract (SKE) is reported to inhibit pancreatic lipase activity in vitro. Therefore, in this work, we investigated the effects of SKE on body weight, visceral fat, and lipid metabolism in mice fed a high-fat diet for 6 weeks. Body weight gain was significantly and dose-dependently suppressed in the groups fed a high-fat diet containing SKE (HF + SKE groups) compared to the high-fat diet control group (HF group). Moreover, Dose-dependent increases in triglyceride (TG) content in feces were observed in the HF + SKE groups. Since we confirmed that SKE inhibits lipase in vitro, these findings indicate that SKE suppresses the hydrolysis of TG by inhibiting lipase activity in the intestinal tract, thereby restricting the absorption of lipids, increasing the excretion of TG in feces, and suppressing the increase in body weight and visceral fat caused by the high-fat diet.