Enhanced flavor–nutrient conditioning in obese rats on a high-fat, high-carbohydrate choice diet

摘要: Abstract Through flavor–nutrient conditioning rats learn to prefer and increase their intake of flavors paired with rewarding, postingestive nutritional consequences. Since obesity is linked altered experience food reward perturbations nutrient sensing, we investigated learning in made obese using a high fat/high carbohydrate (HFHC) choice model diet-induced (ad libitum lard maltodextrin solution plus standard rodent chow). Forty were maintained on HFHC induce substantial weight gain, 20 chow only (CON). Among rats, individual differences propensity gain studied by comparing those the highest proportional (obesity prone, OP) lowest resistant, OR). Sensitivity was tested protocol. To measure initial, within-meal stimulation flavor acceptance post-oral first, sessions 1–3, baseline licking measured while consumed grape- or cherry-flavored saccharin accompanied intragastric (IG) water infusion. Then, next three test they received opposite 5 ml IG 12% glucose. Finally, after additional alternating between two flavor-infusion contingencies, preference two-bottle without infusions. HFHC-OP showed stronger initial enhancement first glucose infusion than CON HFHC-OR rats. OP also most strongly preferred glucose-paired choice. These versus OR suggest that responsiveness postoral reward, consistent view perpetuates overeating obesity.