Gastric Emptying of Indigestible versus Digestible Oils and Solid Fats in Normal Humans

Recent scintigraphic studies indicate thatlipolytic products in the small intestine do not inhibitgastric emptying of fat as potently as previouslysuggested by studies that compared a liquid indigestible oil with a solid digestible fat. The olderstudies left open the confounding possibility that solidfats emptied differently than liquid oil. We studiedeight normal subjects who ingested four meals in which fat was (1) liquid, digestible Criscooil, (2) liquid, indigestible sucrose polyester oil, (3)digestible, solid Crisco, and (4) indigestible, solidolestra. Fats were labeled with iodine-123, and their gastric emptying was followed with agamma camera. Indigestible fats (whether liquid orsolid) emptied consistently faster than digestible fats(P < 0.005), although differences were small. Solid fats emptied about as rapidly as oils in thefirst hour; but more slowly thereafter (P < 0.01). Acomparison of present scintigraphic with older studiessuggested that solid fats were not well tracked by duodenal, marker-perfusion techniques, whichmisled previous investigators.