AJP - Endocrinology and Metabolism, Vol 250, Issue 2 144-E147, Copyright © 1986 by American Physiological Society
Effect of meal size and frequency on postprandial thermogenesis in dogs
J. LeBlanc and P. Diamond
The influence of meal size and frequency on postprandial thermogenesis was
studied in nine mongrel dogs (congruent to 18 kg). Oxygen uptake (VO2) and
respiratory quotient (R) were continuously monitored by indirect
calorimetry during the following experiments. In expt 1, four dogs were fed
on alternated days either a large (3.1 MJ) or small meal (0.77 MJ). In expt
2, five different dogs were fed on alternated days either one large meal
(3.1 MJ) or four consecutive small meals (0.77 MJ) spaced at 1.5-h
intervals. In expt 3, the four dogs of expt 1 after being sham fed 3 times
at 1.5-h intervals were given one large meal (3.1 MJ). The VO2 increase
during the initial or cephalic phase (congruent to 50 min) was independent
of the meal size but it was directly proportional to the amount of food
ingested during the digestive phase. The total thermogenic response to four
small meals (125 g) fed at 1.5-h intervals was twice as large as that of
one large meal (500 g). One large meal (500 g) preceded by three periods of
sham feeding was also found to be more thermogenic than a large meal only.
For all experiments the changes in R were seen to parallel the postprandial
fluctuations in VO2. These findings indicate that the enhanced heat
production obtained when meal frequency is increased is caused by the
repeated sensory stimulation produced by palatable food.
