The glycemic index (“GI”) of a food refers to the magnitude with which the food elevates an individual’s blood glucose levels, and this value can be used to calculate the glycemic load (“GL”) of a specific portion of food. Some evidence suggests that blood glucose levels may play a key role in self-control. Emerging research suggests that consuming low GI or GL breakfasts may enhance memory performance and result in greater levels of positive affect compared to high GI or GL breakfasts. Participants in the present study were randomly assigned to consume either a low GI/GL breakfast or a high GI/medium GL breakfast. Later in the morning, participants completed a memory task, a Stroop task to assess self-control, and a PANAS questionnaire to assess mood. Breakfast condition did not influence memory performance or self-control; however, participants who consumed the high GI/medium GL breakfast indicated significantly higher levels of positive affect than those who consumed the low GI/GL breakfast. Effects of semester on self-control performance and positive affect were observed and are discussed. While contrary to previous research, the present study suggests no comparative cognitive benefit of a low GI breakfast and that a high GI breakfast, when consumed according to serving size recommendations, may not be detrimental to cognitive functions
