Gastric emptying rate of the water and fat phases of a mixed test meal in man.

Abstract

Most reported studies of gastric emptying in humans have been concerned primarily with the regulation of pyloric passage of a single-phase meal. However, Wiggins and Dawson (1961) sampled intestinal contents in man after ingestion of a mixed meal, and found that the proportions of fat and water recovered were different from those of the meal. Harkins, Longenecker, and Sarett (1964) observed in rats that the fat and water phases do not leave the stomach in parallel, fat being retained longer. The present study was conducted in an attempt to elucidate some of the mechanisms involved in this phenomenon and to investigate the effect of fat on the gastric emptying rate of the water phase of a mixed meal. CLINICAL METHODSTen healthy, asymptomatic human volunteers between the ages of 18 and 26 years were studied; three were females and seven were males. They fasted overnight and the experiments were carried out in the morning between 8.45 and 10 the next day. Seven experiments were performed on separate days in each case, five with different test meals and two in different body positions. Three of the test meals (I, II, and III) contained only the water phase but were of different volumes. Two were mixed meals (IV and V) and contained different volumes of fat. Test meal IV was given three times: with the subject sitting, and in the right and left lateral recumbent position.The five meals administered to each subject were as follows: I, 250 ml water phase only; II, 300 ml water phase only; III, 350 ml water phase only; IV, 250 ml water phase mixed with 50 ml olive oil; and V, 250 ml water phase mixed with 100 ml olive oil. The water

The Movement of an Unemulsified Oil Test Meal and Aqueous‐and Oil‐phase Markers Through the Intestine of Normal and Bile‐diverted Rats

“…This finding of faster gastric emptying of the aqueous phase confirms the finding of earlier workers [Wiggins & Dawson, 1961;Chang, McKenna and Beck, 1968;Harkins, Longenecker and Sarett, 1969]. However, there was a slight but consistent excess of triether over 14C activity in the gastric contents.…”

The effect of fat on calcium absorption from a mixed meal in normal subjects, patients with malabsorptive disease, and patients with a partial gastrectomy

“…This may be because in subjects with an intact stomach, sitting erect as was usual during the test, 47Ca C12 may not enter the small intestine at the same time as the fat. Different rates of emptying of the lower aqueous and upper lipid phases of a mixed meal have been observed (Wiggins and Dawson, 1961;Chang, McKenna, and Beck, 1968). In patients with rapid gastric emptying, the fats will be more likely to enter the small intestine mixed with the 47Ca Cl2 and other components of the aqueous phase of the meal.…”

“…In patients with rapid gastric emptying, the fats will be more likely to enter the small intestine mixed with the 47Ca Cl2 and other components of the aqueous phase of the meal. In normal subjects, on the other hand, the '7Ca Cl2 in the aqueous component ofthe meal might be expected to enter the small intestine and be at least partly absorbed before the fat had left the stomach (Chang et al, 1968).…”

Gastric emptying of the liquid, solid and oil phase of a meal in normal volunteers and patients with Billroth II gastrojejunostomy

“…This is caused by methodological problems in labelling fats because most dietary fats are liquefied at room temperature. In normal subjects, fat empties more slowly than liquids [12,13], whereas extracellular fat seems to empty as an oil phase at a rate similar to an equicaloric digestible solid meal [14]. The mechanisms for these observations are still unknown, but it has been suggested that the slower emptying of fats may be due to the formation of a layer of oil on top of the liquid phase of the meal as a consequence of gravity [13].…”

“…In normal subjects, fat empties more slowly than liquids [12,13], whereas extracellular fat seems to empty as an oil phase at a rate similar to an equicaloric digestible solid meal [14]. The mechanisms for these observations are still unknown, but it has been suggested that the slower emptying of fats may be due to the formation of a layer of oil on top of the liquid phase of the meal as a consequence of gravity [13]. However, although gravity may have a major effect on the intragastric distribution of oil, there is relatively little effect on total stomach emptying of oil [15].…”