The response to diets of different nutrient densities was evaluated in male turkeys. In 2-week experiments with 1-week-old and 14-week-old turkeys the growth response to nutrient density appeared to be biphasic with an accelerated response at the lower and a much smaller response at the upper range of nutrient density. Results suggest that the upper limit of nutrient density for obtaining the accelerated growth response was higher for older (14-week-old) than for younger (1-week-old) birds. In two additional experiments, the growth response at the upper energy range was estimated at 1 to 2% per 100 kcal. In 14-week-old turkeys, abdominal fat did not change with nutrient density.