Enhanced thermogenesis during recovery from diet-induced weight
gain in the rat.
Almeida, Nelson G., David A. Levitsky, and Barbara Strupp.
Division of Nutritional Sciences, Savage Hall, Cornell University,
Ithaca, New York, 14853-6301. Telephone 607-255-3263; Fax 607-255
-1033, Centro de Investigacion en Alimentacion y Desarrollo, A.C.,
Apdo. Postal 1735, Hermosillo, Sonora 83000, Mexico, Department of
Psychology, Cornell University, Ithaca, New York
APStracts 3:0210R, 1996.
The present study examined the contribution of energy expenditure to
the recovery of body weight following a period of overfeeding. Three
groups of 2-month old female rats (n=24) were fed, respectively, a
10% (w/w) fat diet (control), a 35% (w/w) fat diet (high-fat) or were
force-fed 130% of the control diet (tube-fed). After 30 days all
groups received the control diet for the 18 days of recovery. Both
overfeeding protocols significantly increased weight above control
levels. This difference disappeared following 7 days of recovery.
Increases in resting oxygen consumption, serum T3 levels and the
thermogenic response to norepinephrine were observed at the end of
overfeeding. Serum T3 and resting oxygen consumption returned to
control levels by day 3 of recovery from overfeeding, while the
thermogenic response to norepinephrine required 9 days to recover.
Whereas total energy expenditure was not significantly elevated
during overfeeding, significant increases of 9.6% and 13.9% were
observed in the formerly high-fat and tube-fed animals respectively
during recovery. These data indicate that changes in energy
expenditure play an imporant role in maintaining the stability of
body weight.
Received 31 January 1995; accepted in final form 13 May 1996.
APS Manuscript Number R80-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 17 June 96