Strain variation in lean mass of ILSXISS recombinant inbred (RI) mice under ad libitum (AL) and 40% dietary restriction (DR) diets. Lean mass was obtained using quantitative magnetic resonance (QMR) from ILSXISS recombinant inbred (RI) mice aged 15–17 months after they were under AL or DR diet since 2–5 months of age. The mean lean mass in the upper two panels are shown for each strain [AL (□) and DR (■)], ranked in ascending order according to the AL means (A. males, 38 strains; B. females, 33 strains). Insets in panel A and B: the mean lean mass of all strains. Panels C (males) and D (females) illustrate the difference of lean mass between AL and DR, ranked from the strain with the greatest reduction in lean mass under DR to the strain with the least reduction (* p < 0.05, ** p < 0.01, *** p < 0.001 by t-test; no experiment-wise Bonferroni correction). Error bars represent SEM.