Obesity has progressively become a global concern. It contributes to adipose tissue dysfunction, leading to metabolic disorders, and chronic systemic inflammation. Our previous study showed that the conjugation between chitooligosaccharides (COS) and epigallocatechin-3-gallate (EGCG) diminished lipid accumulation and promoted browning of white adipose tissue (WAT) in high fat diet (HFD)-induced obese rats.