Body Mass Index and Cognition: A Scoping Review

Body mass index (BMI) is a measure of body fat calculated by dividing weight in kilograms by height in meters squared. Cognition refers to various intellectual functions like memory, reasoning, and problem-solving. The connection between BMI and cognition is complex. Some studies suggest that having a higher BMI is linked to cognitive decline and an increased risk of dementia, while others have found no clear correlation or even suggest that being overweight or obese may have a protective effect later in life. The impact of obesity on cognition may involve factors such as vascular health, inflammation, insulin resistance, and nutrition. It is important to note that lower BMI is associated with an increased risk of dementia in older adults, while midlife obesity is linked to cognitive decline. Sedentary lifestyles can contribute to obesity, which can affect both cognition and motor performance. To counteract these effects, exercise is proposed as a treatment regimen that can help alleviate obesity-related cognitive and motor impairments. The link between obesity and reduced cognitive functions has significant implications for an ageing population. More research is needed to understand the interventions like exercise which improves cognitive functions in the context of BMI variations.