Intestinal fat suppressed intake of fat longer than intestinal sucrose

Although animals eventually stop eating when only experiencing the oro-sensory stimuli from a food, they stop eating much more rapidly if they also receive postgastric stimuli simultaneously. This suggests that the postgastric effects of a nutrient influence the hedonic value of food or motivation to consume that food, and thus, can influence food selection within the time frame of a meal. In this experiment, rats were equipped with a gastric fistula and duodenal cannula. This combination allowed them to receive the same oro-sensory stimuli, but different postgastric nutrients. While ingesting either a fat (Intralipid) or carbohydrate (sucrose) solution, both of which drained from the gastric fistula, the rats received a duodenal infusion of either sucrose (10 mLs, 0.24 kcals/mL), fat (10 mLs, 0.25 kcals/mL) or saline (10 mLs, 0 kcals/mL). While ingesting the Intralipid, a duodenal infusion of fat suppressed intake quicker and longer than an infusion of sucrose. While the animals ingested sucrose, sucrose and fat suppressed intake equivalently.