FIGURE 1.

Aged rats (30 months old) have much less muscle mass, but greater body weights than adult (4 months old), and dietary restriction decreases this loss of muscle. A, boxplots illustrate the body weights of 10 adults (Ad-AL) and 10 aged rats fed AL (Ag-AL) or 9 aged rats maintained on dietary restriction (Ag-DR), as described under “Materials and Methods.” B, soleus muscle weight (mg) at 4 and 30 (AL and DR) months. C, ratio between soleus weights (mg) and body weights (g). Box limits represent upper and lower quartile values and are separated by the median (crossbar within box). Maximum and minimum values, which are not defined as outliers (circles), are illustrated using error bars. Outliers are defined as values deviating from the quartile borders by more than 1.5 times the interquartile distance. ***, p < 0.001.