Provided in the present invention is a use of a composition containing an iron (II) amino acid chelate in preparing a drug for regulating and controlling the fat metabolism, wherein the drug comprises an effective dosage of a composition containing an iron (II) amino acid chelate for regulating and controlling the fat metabolism and a pharmaceutically acceptable carrier thereof. In the composition containing an iron (II) amino acid chelate of the present invention, the amino acid, maintaining the chelate state thereof with the iron (II), can pass through the stomach, and can effectively control the body weight change of a recipient and promote body fat decomposition and the drug prepared from the composition containing an iron (II) amino acid chelate of the present invention has the effect of regulating and controlling the fat metabolism.