Day-to-day variation in glycemic response elicited by white bread is not related to variation in satiety in humans

Low-glycemic index foods are often thought to be highly satiating because of their low glycemic response, but the effect could be due to confounding factors. To see whether satiety was related to day-to-day variation of glycemic responses after a standard test-meal, glucose and satiety responses were measured in 23 non-obese subjects after portions of white bread containing 25 g (WB25) or 50 g (WB50) available-carbohydrate. Each subject tested each dose of WB on at least three different occasions. Satiety responses for the tests with the highest (HiAUC) and lowest (LoAUC) glucose area-under-the-curve (AUC) for each dose of WB were subjected to analysis of variance examining for the effects of sex, time, WB dose and glucose AUC. Glucose AUC after WB25 was 58% of that after WB50 (88 ± 6 mmol min/L vs. 151 ± 11 mmol min/L, p < 0.001) and glucose AUC for LoAUC was 52% of HiAUC (82 ± 7 vs. 157 ± 10, p < 0.001). Satiety AUC after WB25 was less than after WB50 (3260 ± 729 mm min vs. 5640 ± 780 mm min, p = 0.003) but satiety AUC for LoAUC was similar to HiAUC (4430 ± 700 mm min vs. 4480 ± 683 mm min, ns). The results were similar for males and females. These results do not support the hypothesis that glycemic responses per se influence feelings of satiety over the 2 h period after eating.