AJP - Regulatory, Integrative and Comparative Physiology, Vol 247, Issue 2 387-R392, Copyright © 1984 by American Physiological Society
Effects of repeated isocaloric macronutrient loads on daily food intake of rats
A. Geliebter, J. T. Liang and T. B. Van Itallie
The effects of repeated administration of different macronutrient loads on
spontaneous food intake and body weight of male Sprague-Dawley rats were
studied. For 6 wk, eight groups of five rats each received two daily
intragastric loads, 3.5 h apart, consisting of isocaloric amounts of one of
the following: albumin, sucrose, cornstarch, corn oil, a mixture of the
preceding four loads, butter, medium-chain triglyceride, or a noncaloric
load of water. Spontaneous intakes of rat chow were measured 3.5 and 24 h
after the first daily load. All the macronutrient loads depressed
subsequent 3.5-h intakes more than the water load (P less than 0.01), and
protein loads depressed 3.5-h intakes the most (P less than 0.01). The
macronutrient loads also depressed 24-h intakes more than water loads (P
less than 0.01) but did not differ among themselves. The mixture load
depressed 3.5- and 24-h food intakes by an amount comparable with the
average effects of its component loads. Neither body weight nor body fat as
measured by the Lee index differed among the groups after 6 wk. The results
indicate that fairly accurate long-term regulation of spontaneous energy
intake occurs regardless of the type of macronutrient in the load.
