In Kisangani, to understand the mechanism linked to the use of dietary lipids, a study was carried out in 2011, on the species Oreochromis niloticus.180 fish with an average weight of 3.4 g for the control and 3.14 for the test batch were tested in an experimental system in duplicate with food containing 30% crude protein where a diet was supplemented with 12% lipids for 30 days.After analyzing the results we noticed the following: It turned out that the fish doubled in weight during the experiment in the order below 4.21 ± 5.74 for food R12 and 5 .7 ± 3.27 for food R0.A non-significant difference (p<0.05) could be demonstrated according to the STUDENT t test, between the gain in body mass of the fish fed with the R0 diet and those fed with the R12 diet.The SGR (specific growth rate) is significantly correlated with diet. The weekly consumption was not constant, and without significant increase during the experimental period.