This is an observational study to explore the etiology and clinical classification in patients with obesity and to achieve personalized treatment.

In this project, individuals with obesity and control individuals were recruited and followed up every year. Clinical neuropsychological scores, olfactory function tests, and functional magnetic resonance imaging (fmri) were performed to describe the brain function characteristics under different odor stimulation in fasting and after eating, and to explore the pathogenesis and clinical classification of obese patients. The correlation analysis between imaging analysis values and clinical laboratory data, neuropsychological scores and olfactory behavior scores was performed to explore indicators related to cognitive decline and provide new insights into the etiology and classification of obese patients. Combined with clinical evaluation and imaging examination, the changes of cognitive behavior and brain structure and function in obese patients were followed up.

Inclusion Criteria:

• Patients with BMI≥28kg/m2
• Aged 18-65 years of both sexes, right-handed
• At least 6 years of education
• Patients agreed and signed the informed consent

Exclusion Criteria:

• Fewer than 6 years of education
• Left-handedness
• Dementia
• Acute metabolic complications such as diabetic ketoacidosis
• Hyperglycaemic hyperosmolar state and hypoglycaemic coma within the previous 3 months; history or presence of neurological or psychiatric disorders;
• Presence of hypothyroidism;
• History of malignancy, or severe kidney or liver dysfunction.

This study is a dynamic prospective cohort study.