voluntary certification is preferred by many employers. in canada, dietary managers with recognized training in areas such as diet therapy, menu planning, food safety and food production may become members of the canadian society of nutrition management (csnm). in the united states, "certified dietary managers" are certified by the credentialing agency known as the association of nutrition & foodservice professionals (anfp). this agency also certifies a professional known as a "certified food protection professional". the anfp certifies specific programs to meet its educational requirements, including courses in culinary management, clinical nutrition, and food safety. in addition, there are supervised practice requirements and a certification exam that must be passed. dietary hosts dietary hosts/hostesses, also known as "food service aides", assist in patient tray services in hospitals and other health care settings, usually under the supervision of the dietary manager. they distribute menus, and prepare, deliver and bring back meal trays. usually no specific training is required for workers in this category.