This study is a prospective, single-center, randomized, controlled, crossover intervention trial. A total of 60 participants, including 30 patients with obesity and 30 healthy controls, will be enrolled. Each participant will receive an isocaloric liquid meal challenge (glucose, fat, or protein) on three separate experimental days, with a washout period of at least 7 days between visits to eliminate carryover effects from the previous intervention. The primary objective is to investigate the association between brain functional patterns and plasma metabolic profiles following the ingestion of different macronutrients in patients with obesity, aiming to uncover potential neuro-metabolic imbalance features.