Figure 1. Study design, lifespan and metabolic phenotypes of mice under different dietary regimens. (A) The study design. NF mice had ad libitum access to normal chow. HF mice had ad libitum access to a high-calorie diet. (B) Food intake and calorie intake were calculated based on the daily food consumption of mice during the intervention (n=30 per group). (C) A line plot showing the average weekly weight in grams (mean ± SEM) of mice under different conditions (n=30 per group). HF mice gained weight, whereas HDR mice, despite being on a high-calorie diet, were indistinguishable from NF controls. (*P<0.05, compared to group NF). (D) Kaplan-Meier survival curves (n=30) showing significant difference in the lifespan between interventions according to the log-rank test (P<0.001). (E) Mean and maximum lifespans of mice in the five intervention groups as calculated from the Kaplan-Meier survival curves. The maximum lifespan was calculated as the average of the oldest 20% of mice in each group. (F) Oxygen consumption, (G) respiratory exchange ratio (CO2 exhaled/O2 inhaled), and (H) heat production at different ages (n=5 per group). #P<0.05, ##P<0.01, ###P<0.001 vs the HF group; *P<0.05, **P<0.01, ***P<0.001 vs the NF group according to ANNOVAS.