Effects of orosensory stimulation on postprandial lipemic and thermogenic responses in humans
Abstract
This study assessed the effects of orosensory stimulation by equipalatable stimuli that differed in macronutrient content (lipid and carbohydrate) on postprandial triacylglycerolemia and thermogenesis. Sixteen healthy normal weight adults (8 male, 8 female) participated in six test sessions conducted weekly. The test sessions were administered randomly after overnight fasts and included: ingestion of 50 grams of butter in capsules (to avoid oral stimulation with lipids) and 500ml of water in 15 minutes followed by no oral stimulation or oral stimulation with one of the following foods on a cracker: butter, unsaturated fatty acid (UFA) margarine, jelly, UFA margarine + jelly. Sensory stimulation entailed masticating and expectorating approximately 5.Og samples of each stimulus every 3 minutes for 110 minutes. During the 110 minute period of intermittent oral stimulation, respiratory gas exchange was measured from minutes 25 to 35 and 60 to 70. Upon termination of the oral stimulation period, respiratory gas exchange was measured continuously for an additional 5.5 hours. Blood was drawn immediately after preload ingestion and at minutes 35, 85, 200, 320, and 440 postloading and was analyzed for triacylglycerol, insulin, glucagon, and glucose. No significant treatment differences were observed for thermogenesis or oxidation of carbohydrate or lipid. Only the oral samples containing the UFA margarine led to significant elevations of serum triacylglycerol concentration compared to baseline (p < 0.05). Insulin, glucagon, and glucose concentrations were not different between treatments. These data suggest that orosensory stimulation with stimuli differing in lipid and carbohydrate content, but rated similarly in palatability, do not elicit an increased or differential diet-induced thermogenic response. However, oral exposure specifically to an unsaturated dietary lipid augments the postprandial rise of TAG.
Degree
Ph.D.
Advisors
Mattes, Purdue University.
Subject Area
Nutrition
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