A 70% ethanol-water extract from the leaves of Mangifera indica L. (Anacardiaceae) inhibited triglyceride (TG) accumulation in 3T3-L1 cells. From the active fraction, seven new benzophenone C-glycosides, foliamangiferosides A (1), A(1) (2), A(2) (3), B (4), C(1) (5), C(2) (6), and C(3) (7), together with five known compounds were isolated and the structures were elucidated on the basis of chemical and physicochemical evidence. The effects of these compounds on TG and the free fatty acid level in 3T3-L1 cells were determined, and the structure-activity relationship was discussed. On the basis of the AMPK signaling pathway, several compounds were found to increase the AMPK enzyme expression and down-regulate lipogenic enzyme gene expression such as SREBP1c, FAS, and HSL.