Diet and starvation on the composition and calculated density of fat-free body mass.

The density of the fat-free body mass (FFM) was calculated from carcass composition and density of body components in 148 growing rats under different dietary conditions. These conditions were controlled feeding with 20% and 5% casein diets during 6 and 9 wk, followed by 5 days of starvation, and after starvation with 2 wk refeeding with 20 and 5% casein diets. The results showed that the density of FFM was fairly constant. The means and standard deviations for all conditions were 1.0965 +/- 0.0057 and 1.0956 +/- 0.0075, for the 20% and 5% casein groups, respectively, with a grand mean of 1.0960 +/- 0.0066. It was concluded that the assumption of a constant density of FFM holds very well for many dietary and experimental conditions.