Figure 4. Metabolic rate as assessed by indirect calorimetry performed over a 24 hour period.

The dark period is shaded. (A) Metabolic rate for 3-month-old female mice (n = 13). (B) Metabolic rate for 3-month-old male mice (n = 12). (C) Metabolic rate for 2-year-old female mice (n = 19 and 21). (D) Metabolic rate for 2-year-old male mice (n = 17 and 18).