SirT1 and Caloric Restriction Figure 1. SirT1-null mice are hyperphagic. A. Body weights of sibling animals of normal (SirT1+/+ and SirT1+/2) and SirT1(2/2)-null genotypes at 2–4, 5–8 and 13–20 months of age. B. Daily food intake of mice as described in A. C. Daily food intake normalized to body weight. D. Caloric content of feces from 2–4 months old normal and SirT1-null mice. Means and standard errors are represented along with the number of animals used for each determination. Unpaired T-tests were performed to assess statistical significance. doi:10.1371/journal.pone.0001759.g001 PLoS ONE | www.plosone.org 2 2008 | Volume 3 | Issue 3 | e1759