Dissociation of enhanced efficiency of fat deposition during weight
recovery from sympathetic control of thermogenesis.
Dulloo, A. G., J. Seydoux, and L. Girardier.
Department of Physiology, Centre Medical Universitaire, University
of Geneva, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland
APStracts 2:0082R, 1995.
Studies reported here examined the extent to which conditions known to
suppress or to markedly increase the sympathetic control of
thermogenesis influence the enhanced efficiency of fat deposition
during weight recovery after caloric restriction. To this end,
measurements of energy balance and changes in body energy
compartments during refeeding of rats pair-fed with weight-matched
controls were conducted over a two-week period at 22 degrees C, at
thermoneutrality (29 degrees C) or in the cold (6 degrees C). The
results indicate that despite identical (or slightly lower) energy
intake relative to the respective controls, the refed animals showed
greater gain in body fat (by 2-2.5 fold), 10-12% lower energy
expenditure, and higher energetic efficiency (60-80%) than the
controls at all three environmental temperatures. In contrast,
protein gain was not different between the refed and control groups.
Thus the energy-conserving mechanism specific for accelerating fat
deposition during weight recovery persists when sympathetically
-driven thermogenesis is shifted from very low to very high intensity.
These findings raise the possibility that this energy-conserving
mechanism during refeeding may be distinct from sympathetic-dependent
mechanisms underlying adaptive reduction in thermogenesis during
severe energy deficit and weight loss.
Received 18 October 1994; accepted in final form 15 March 1995.
APS Manuscript Number R619-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 April 1995.