Figure 3.

Reduced energy expenditure in SIRT1^+/− mice on HFD. The mice were fed on HFD at 12 wk of age, and examined for energy expenditure after 3 wk on HFD. A, Time course of body weight gain. Body weight was weighed every 2–4 wk from 12 wk of age. B, Fat mass. C, Lean mass. D, Food intake. Food intake was monitored daily for 3 d. Average daily food intake (g) was converted into kilocalories and normalized with lean body mass (kg) and time (hours). E, Energy expenditure in SIRT1^+/− mice. Energy expenditure was examined using the metabolic chamber and normalized with lean body mass. F, Fatty acid utilization normalized with lean body mass. G, Carbohydrate utilization normalized with lean body mass. H, RER is a volume ratio of oxygen consumed vs. CO₂ exhaled. In this figure, values are the means ± se (n = 7). *, P ≤ 0.05.