A peptide and a peptide complex of the present invention exhibit an anti-obesity effect by inhibiting fat accumulation and decomposing already accumulated fat, and exhibit an excellent effect with respect to diabetes by effectively reducing blood sugar. The peptide and the peptide complex of the present invention decrease the expression of PPAR³, ACC, and aP2, which are adipogenic markers, increase the expression of pHSL, AMPK-±1, CGI-58, and ATGL, which are lipolytic factors, and reduce the size of fat cells and blood cholesterol values. The peptide and the peptide complex of the present invention, which have excellent activity and safety, can be advantageously applied to drugs and quasi-drugs.