Consumption of a low glycemic index (GI) diet has been shown to improve glycaemic control in type 2 diabetics(Brand−Miller et al., 2003; Jenkins et al., 2008). In addition to the benefits for glycaemic control there is some evidence for acute improvements in cognitive performance after consumption of low GI foods compared with high GI foods in both adults (Benton et al., 2003; Kaplan et al., 2000) and adolescents (Ingwersen et al., 2007; Smith and Foster, 2008).