Body composition, heat production (HP), and activity were measured by DEXA, indirect respiration calorimetry, and motion detectors at 6 month intervals in 30 adult male rhesus monkeys for a study of the effects of moderate dietary restriction (DR) on aging. All animals were fed a defined diet, with the restricted (R) animals maintained at approximately 70% of the ad libitum intakes of the control (C) monkeys. After 12 months of DR, body fat mass (FM) of R monkeys was 33% less than that of C (p=.004). After 36 months, FM, lean body mass (LBM) and percent body fat were also significantly lower (p<.05) in R compared to C and these differences were maintained through 66 months of study. At the 24 and 30 month assessments, night-time HP was reduced by 17% (p=.0012) in the R compared to C after adjustment for LBM differences, while morning, afternoon and total HP were not significantly different (p>.05). R monkeys also had lower HP than C after adjustment for FM (p=.028) and total body mass (p=.13) in addition to LBM. At the 42 - 66 month assessments, HP adjusted for LBM, FM or total body mass was not significantly different (p>.10) between R and C monkeys at any time of day. No significant difference (p>. 10) in activity was observed between treatment groups at any time during the experiment. DR resulted in an initial decrease in nighttime or resting HP which was not detectable after 42 months of the experiment. This suggests that if decreased HP is a mechanism of action of DR. it must be the result of tissue soecific instead of whole animal changes in energy metabolism.
|Original language||English (US)|
|State||Published - 1996|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology