Calorie Restriction Promotes Constant Physical Activity Levels Throughout Total Lifetime of Female Mice: 3064 Board #5 June 2 9 00 AM - 11 00 AM

BACKGROUND: Physical inactivity contributes to incidence of diseases and decreased life expectancy. Previous data has shown that chronic overfeeding via high fat high sugar diet (HFHS) reduces voluntary wheel running (WR) activity in mice. PURPOSE: Determine the effects of a 12% calorie restriction diet (DR) vs. an ad-lib HFHS diet on physical activity (PA) levels (distance, duration, speed) throughout total lifetime in female SENCAR mice. METHODS: SENCAR mice were bred and offspring were weaned at 3 weeks of age onto a HFHS (20% protein, 45% fat, 24% sucrose + 10% fructose water), an ad-lib standard chow (CONT; 20% protein, 10% fat, 57% cornstarch), or a DR (12% kcal restriction, 20% protein, 10% fat, 57% cornstarch). At 4 weeks of age, female mice were housed in pairs and two plastic running wheels were mounted inside each cage. WR distance (km/day) and duration (min/day) were recorded and used to calculate average speed (m/min) via a mounted computer system. Repeated measures ANOVA determined the effect of diet on WR activity relative to varying percentages of total lifetime (15%, 25%, 50%, 75%, and 100%). RESULTS: 116 female mice [HFHS (n=42), DR (n=55), CNTL (n=19)] were analyzed. Both ad lib HFHS and ad lib CONT diets significantly decreased distance, duration, and speed after 25% of the total lifespan. All PA variables remained unchanged for the DR mice with the only significant reduction occurring in duration between 75% (221 ± 98min/day) to 100% (188 ± 79min/day) of total lifetime. Additionally, correlations of determination were observed for body weight vs HFHS (.44), DR (.04), and CONT (.34) diets. CONCLUSIONS: DR mice maintained activity levels across their lifespans as compared to ad lib CONT and ad lib HFHS mice whose activities decreased over their lifespan. These findings substantiate our previous data and propose that minimal calorie restriction may serve a novel intervention to prevent physical inactivity across the lifespan.