The number of chews and meal duration affect diet-induced thermogenesis and splanchnic circulation

Objective To determine the effects of the number of chews and meal duration on diet-induced thermogenesis (DIT) and splanchnic blood flow (BF). Methods Healthy normal-weight subjects (11 subjects in the 100-kcal test and 10 subjects in the 300-kcal test) participated in two trials: a rapid-eating trial and a slow-eating trial. The meal duration and the number of chews were recorded. DIT was calculated from oxygen uptake and body mass, and splanchnic BF was calculated from the diameters of and blood velocities in the celiac artery and superior mesenteric artery, which were recorded until 90 min after consuming the food samples. Results For the 100-kcal and 300-kcal food samples, DIT and postprandial splanchnic BF in both the celiac artery and superior mesenteric artery were significantly larger in the slow-eating trial than in the rapid-eating trial. There were significant correlations among meal duration, the number of chews, DIT, and postprandial splanchnic BF, with the exception of the relationship between DIT and splanchnic BF in the 300-kcal trial. Conclusions These results suggest that fewer chews and/or shorter meal duration decreases DIT and the postprandial splanchnic BF, and that the increased DIT is at least partially due to the postprandial splanchnic circulation.