Abstract: The present invention relates to use of a composition for the manufacture of a medicament and a method for inhibiting the formation of body fat. The composition includes lactoferrin and a trivalent chromium compound. Herein, the chromium compound is selected from the group consisting of chromium (III) chloride hexahydrate, chromium (III) chloride, chromium (III) acetate, chromium (III) sulfate, chromium picolinate, chromium nicotinate, chromium GTF, chromium yeast extract, other inorganic salts of trivalent chromium, other organic salts of trivalent chromium, and combinations thereof. Accordingly, the composition of the present invention can assist in transmitting glucose from cells to muscle tissues and thereby reducing the storage of fat converted from glucose to achieve the purpose of controlling body weight.