The purpose of this part is to provide for improved levels of nutrition among economically needy households through a cooperative federal-state program of food assistance to be operated in such counties of this state as may be certified by the department of human services and designated by the secretary of the United States department of agriculture, or its successor agency, to participate in the food stamp program in accordance with the requirements of Public Law 88-525 (7 U.S.C. § 2011 et seq.), and any amendments to that law or any other subsequently enacted federal statutes on the same subject.