This study aims to understand how adipose tissue (fat) and the gut microbiota (the bacteria in the gut) may influence brain function and cognition. It has been observed that changes in adipose tissue in animals such as mice and Drosophila (a type of insect) affect memory and other brain functions. Additionally, it is believed that the gut microbiota also plays an important role in cognition. This study will explore how gene expression in adipose tissue, blood metabolites, and the gut microbiota are related to cognitive function, such as memory and thinking, in individuals with and without obesity. The investigation will also assess whether these factors can predict changes in the brain over time and how they influence sleep, physical activity, and blood sugar regulation. Advanced technologies will be used to analyze samples of tissue, blood, and microbiota, with the goal of identifying new mechanisms through which obesity affects the brain. This research may contribute to the development of new diagnostic and therapeutic strategies for cognitive problems in individuals with obesity.