Energy expenditure of adult male rhesus monkeys during the first 30 months of dietary restriction. Ramsey, Jon J., Ellen B. Roecker, Richard Weindruch, and Joseph W. Kemnitz. Wisconsin Regional Primate Research Center, University of Wisconsin-Madison, Madison, WI 53715-1299, Department of Medicine, University of Wisconsin-Madison, Madison, WI 53792-2454, Department of Biostatistics, University of Wisconsin-Madison, Madison, WI 53706, GRECC, Wm. S. Middleton VA Medical Center, Madison, WI 53705
APStracts 4:0028E, 1997.
Energy expenditure, activity, and body composition were measured in thirty adult male rhesus monkeys used in a study having the long-term goal of determining the effects of moderate dietary restriction (DR) on aging. All animals were fed a defined diet, with the restricted animals maintained at approximately 70% of the caloric intakes of the controls. After 12 months of DR, body fat mass of restricted monkeys was 33% less than that of controls (p=.004), while lean body mass differences were not present until after 24 months. At the 24 and 30 month assessments, nighttime energy expenditure was significantly reduced (p<.01) in the restricted compared to control monkeys after adjustment for lean body mass differences, while morning, afternoon, and total energy expenditure were not significantly different (p>.05). No significant differences (p>.05) in activity were noticed between treatment groups at any time point. DR resulted in a prolonged decrease in resting energy expenditure which could contribute to the possible life-extending action of this treatment.

Received 11 November 1996; accepted in final form 16 January
1997.
APS Manuscript Number E570-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 19 February 1997