Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder associated with numerous complications, including cognitive impairment. Obesity, a common comorbidity of T2DM, further exacerbates cognitive decline. Weight reduction through lifestyle modifications and/or bariatric surgery has been demonstrated to improve metabolic control and reduce diabetes-related complications. However, the specific effects of weight reduction on cognitive function in individuals with T2DM remain underexplored. A comprehensive review of the literature was conducted to investigate the impacts of weight reduction on mental capability in patients with diabetes. Studies published between January 2000 and September 2023 were included, and relevant data was extracted. The search encompassed randomized controlled trials, observational studies, and systematic reviews. Emerging evidence suggests a positive correlation between weight reduction and enhanced cognitive function in individuals with T2DM. Several mechanisms have been proposed, including improved insulin sensitivity, reduced inflammation, enhanced cerebrovascular perfusion, and modulation of neurotrophic factors. Lifestyle interventions, such as dietary modifications and increased physical activity, were associated with notable cognitive improvements, especially in tasks related to executive function, attention, and memory.
