Body composition of the participants in the CR group (n = 143) at 24 mo compared with the AL group participants (n = 75). Participants in the CR group: men, n = 44; women, n = 99. Participants in the AL group: men, n = 22; women, n = 53. Percentage of fat mass and percentage of fat-free mass in the participants in the CR group at 24 mo were not only comparable to those of the men and women in the AL group, but they were significantly higher for percentage of fat-free mass and lower for percentage of fat mass (P < 0.01 for both men and women). AL, ad libitum control; CR, calorie restriction.