Effect of ingestion order of the fat component of a solid meal on intragastric fat distribution and gastric emptying assessed by MRI

Purpose: To develop an MRI technique to investigate how varying the ingestion order of nonfat and fat components of a solid meal influences three-dimensional intragastric distribution and gastric emptying (GE). Materials and Methods: Eight healthy subjects were studied twice in randomized order. On one occasion (condition F-NF), the fat componant (40 g mayonnaise on toast) was served before the nonfat component (270 g pasta, 200 g tomato sauce, 100 mL water), on the other (condition NF-F), the ingestion order was reversed. GE and intrgastric distribution of both components were assessed by MRI for 180 minutes. Results: During condition F-NF, GE of fat was significantly faster than during condition NF-F (T-25 [min]: F-NF: 20 +/- 9; NF-F: 40 +/- 7; P < 0.05), a larger amount of fat was observed in the antrum during condition F-NF, and more fat layering occurred. No differences were observed in total GE between the two conditions. Conclusion: Meal ingestion order influences GE and intragastric distribution of fat, which can be assessed by MRI techniques, providing new insights into the physiology of gastric processing and intragastric distribution of different meal phases.