Glycemic and insulinemic responses as determinants of appetite in humans

The importance of the postprandial glycemic and insulinemic responses for appetite and energy intake (EI) is controversial.

The aim of the study was to test the hypothesis that postprandial appetite sensations and subsequent EI are determined by postprandial glycemic and insulinemic responses after the intake of a range of breakfast meals.

The study was a randomized, crossover meal test including 28 healthy young men, each of whom tested 10 of 14 breakfast meals. Each meal contained 50 g carbohydrate with various glycemic index and energy and macronutrient contents. Blood samples were taken, and appetite sensations were measured 3 h after the meals. Subsequently, EI at lunch (EI(lunch)) was recorded.

The glycemic response was unrelated to appetite sensations, whereas the insulinemic response was positively associated with postprandial fullness (R2 = 0.33, P < 0.05). In contrast, the insulinemic response was unrelated to the subsequent EI(lunch), whereas the glycemic response was positively associated with EI(lunch) (R2 = 0.33, P < 0.05). Although no significant difference in EI(lunch) was observed between different breakfast conditions, a low breakfast EI was associated with a high EI(lunch) (R2 = 0.60, P < 0.001).

The current study does not support the contention that the postprandial glycemic response has an important effect on short-term appetite sensations, but a low-glycemic index meal may reduce subsequent EI. In contrast, postprandial insulin seems to affect short-term appetite sensations.