Tilapia has been called a miracle fish because of it's ability to feed low on the aquatic food chain but it is also capable of utilizing pelleted dry feeds for growth. The aim of this study was to examine the changes in the weight different body parts and the changes in the relative proportions of the major body constituents of T. nilotica raised on natural foods, a pelleted feed or a pelleted feed in combination with natural foods. For each 2-cm group (19-20 to 32-33 cm) fish that had access to both feed and natural productivity attained a greater average whole body weight and dressout weight than fish that only received a pelleted feed. Fish that had access to natural foods only, attained a maximum body length of 25-cm and a lower body weight for each respective 2-cm length group than those fish receiving a pelleted feed. The analyzed natural productivity raised fish had the highest percentage moisture content and the lowest percentage lipid content, for both whole body materia! and fillets. Fish that were able to utilize natural productivity and feed for growth had the highest percentage of protein for both whole body and fillets. With the three types of diets used in this study resulting in three different levels of gain and varying levels of proximate composition, it appears that these preliminary data indicates that the relative changes in body weight and body composition are strongly affected by the type of food consumed.