Background and aims: Diabetes impairs several cognitive domains including executive functions. Impaired neuroplasticity plays a pivotal role in cognitive decline and a mixed meal (MM) boosts neuroplasticity in healthy subjects while this response is blunted in obesity. The aim of the study is to explore the effects of a MM and GLP-1RA on executive functions in diabetes. Methods: 54 individuals with normal glucose tolerance (NGT, age: 38.2±1.7 y, 26.1±0.7 kg/m2, HbA1c: 34.6±0.6 mmol/mol) and 29 type 2 diabetes (T2DM, age: 54.9±1.8 y, 30.9±0.8 kg/m2, HbA1c: 53.7±2.3 mmol/mol) on metformin monotherapy underwent the Montreal Cognitive Assessment (MoCA) test. At fasting and 90 min after MM, a modified colour-based version Stroop test was administered to explore executive functions (selective attention and processing speed) through the response time (RT, sec), in 3 phases with increasing difficulty (LD, lower; MD, medium; HD, high). T2DM repeated Stroop test 3-months after GLP-1RA therapy. Results: T2DM and NGT had similar MoCA score (25.3±0.5 vs 26.6±0.4; p=0.18). At fasting T2DM RT was slower than NGT in all 3 phases (LD: 1.19±0.04 vs 1.07±0.04 sec, p=0.008; MD: 1.45±0.06 vs 1.27±0.05 sec, p=0.015; HD: 1.72±0.05 vs 1.52±0.05 sec, p=0.006). RT shortened after MM in both groups although more in NGT than T2DM independently of age (LD: 1.08±0.05 vs 0.94±0.03, p=0,015; MD: 1.33±0.05 vs 1.16±0.03, p=0.006; HD: 1.63±0.06 vs 1.42±0.04, p=0.003). In both groups mean glucose during MM was positively correlated with RT in all Stroop phases (r: 0.27 to r: 0.35; all p<0.01). After GLP-1RA, BMI and HbA1c decreased (-1.6±0.5 kg/m2, -4.2±1.9 mmol/mol, both p<0.05), MoCA slightly increased (25.3±0.5 to 26.6±0.3; p=0.10), Stroop test at fasting showed a significant improvement of LD phase (1.19±0.04 to 1.05±0.04 s, p=0.04). HbA1c decrease correlated with the decrease of RT at fasting and after MM (r=0.44 and r=0.55; both p<0.05, respectively). In stepwise multivariable analysis, age and HbA1c were an independent risk factors for RT in NGT and T2DM, respectively (F: 18.7, p<0.001 and F: 10.7, both p<0.01). Conclusions: MM activates executive functions in both groups, although a lesser degree in T2DM. The latter have worse executive functions as compared to NGT either at fasting and post MM independently of age. GLP-1RA therapy partially restored the executive functions most likely via improved glycaemic control.