The efficiency of energy utilization for maintenance and growth was derived from feeding white grouper increasing amounts of dietary energy from starvation up to maximum intake. Several growth trials lasting up to 6 weeks were performed using fish of different weights (25 groups, from 6 to 230 g) at the start of the trials. Initial samples of 10–20 fish were taken before each growth trial and all fish were sacrificed at the end of each trial. Energy, protein and lipid gains in fish were determined by comparative slaughter technique, and daily retention of energy, protein and lipid was related to the geometric mean weight of fish.