Figure 2. Sex-specific effects of HFD on lifespan and health of NIH Swiss mice. (A) HFD-induced body weight gain in male and female mice. Feeding HFD results in 40% and 30% increase in body weight in males and females respectively (p<0.001, Student’s t-test). Since mortality is usually preceded by rapid weight loss, data is shown for the initial period of treatment before the first case of death in each group was recorded. Blue line – regular diet; green line – HFD. (B) Feeding HFD reduces lifespan of male mice from 121.1+9.2 to 91.5+5.9 weeks (p=0.008, Kaplan-Meier log-rank test) but had no effect on longevity of female mice (109.6 +6.9 and 104.9+7.7 weeks for mice fed regular or high fat chow respectively). Blue line – regular diet; green – HFD. Red arrow indicates the period of time when mice received HFD. Black arrow indicates time when PFI was measured (at the age of 78 weeks). (C) PFI created at 78 weeks of age using 16 or 18 parameters for male and female mice respectively. Feeding HFD significantly increases PFI of male (p=0.019, Student’s t-test) but not female mice. RDW - regular diet in combination with water (group 1), HFDW – HFD in combination with water (group 3).