Effects of meal volume and posture on gastric emptying of solids and appetite

Abstract

The effects of volume and posture on gastric emptying and intragastric distribution of a solid meal and appetite were evaluated. Eight normal volunteers were studied on four occasions, on each of which a meal comprising ground beef mixed with tomato sauce of either 650 g (“large”) or 217 g (“small”) was eaten. Two studies were performed while the subject was lying in the left lateral decubitus position, and two studies were performed while the subject was sitting so that in each subject data were available for both meals and in both postures. Hunger and fullness were evaluated using a visual analog questionnaire. In both postures and after both meals, gastric emptying approximated a linear pattern after an initial lag phase. The lag phase was shorter for the large meal when compared with the small meal [sitting: large 13 ± 5 vs. small 29 ± 7 min; left lateral: large 16 ± 3 vs. small 24 ± 3 min, F(1,7) = 46.3, P < 0.0005]. In both postures the contents of the total [ F(1,7) = 1794.5, P < 0.0001], proximal [ F(1,7) = 203.7, P < 0.0001], and distal [ F(1,7) = 231.5, P < 0.0001] stomach were greater after the large meal when compared with the small meal. Although the 50% emptying time was greater with the large than the small meal [ F(1,7) = 40.8, P < 0.001], the postlag emptying rate (g/min) was more rapid with the large meal [sitting: large 1.7 ± 0.2 vs. small 1.1 ± 0.1 g/min; left lateral: large 1.8 ± 0.1 vs. small 1.3 ± 0.04 g/min, F(1,7) = 44.7, P < 0.0005]. There was a significant interaction between meal volume and posture for retention in the distal stomach [ F(1,7) = 7.14, P < 0.05]. Contrasts were used to evaluate the effects of volume and posture between the four studies and demonstrated an effect of posture for the large [ F(1,21) = 18.7, P < 0.005] but not the small [ F(1,21) = 0.30, P = 0.60] meal so that the retention was greater in the sitting when compared with the left lateral position. The magnitude of the postprandial increase in fullness [ F(1,7) = 7.8, P < 0.05] and reduction in hunger [ F(1,7) = 5.9, P < 0.05] was greater with the large meal. We conclude that meal volume has a major effect on gastric emptying; in contrast posture has only a minor impact on intragastric meal distribution, which is observed only after a large meal, and no effect on gastric emptying.

Influence of posture on pharmacokinetics

“…In contrast, Spiegel et al found no posture-dependent differences in postprandial hunger after the ingestion of soup and a sandwich (seated vs. supine), which they explained by a different meal composition and a shorter observation period (0-120 min post-ingestion) [12]. After the ingestion of a solid meal (without liquid component), no statistical significant difference in satiety ratings for sitting and left lateral position could be observed [10].…”

“…In terms of the effects of posture on the gastric emptying of solid food, conflicting results have been published. Whereas Asada et al [9] found gastric emptying to be more delayed in the supine position versus the sitting position, Doran et al did not see any relevant influence of posture (left lateral vs. sitting) following the administration of both a small and a large meal [10]. Doran et al concluded that posture has only a minor influence on intragastric distribution and no effect at all on gastric emptying of solid food.…”

Measurement of Gastrointestinal Transit

“…Reporting medical centers have often developed their own techniques. Because technique, especially the composition of the test meal (16,18,32,74), may significantly influence observed gastric emptying, published normal values cannot be easily compared. In a recent multicenter study, Tougas et al (71,72) used a standard homogenized egg substitute which was similar in properties to eggs.…”

Effect of Postprandial Posture on Digestion and Absorption of Dietary Carbohydrate.

“…H o w e v e r , t h e r e i s n o a g r e e m e n t a m o n g t h e i r experimental results. Asada et al (1989) and Moore et al (1988) reported an association between postprandial sitting position and the faster gastric emptying of solid meals, but Doran et al (1998) showed that the major effect of meal volume had a greater effect on gastric emptying than postprandial posture.…”