**4. Conclusion**

Obesity and MetS are becoming global diseases. The mechanisms by which MetS is caused have been elucidated. It is now comprehended that insulin resistance and mild chronic inflammation elimination are critical for MetS improvement and prevention and that augmenting brown and beige fat cells, which secrete batokines and improve insulin resistance, are vital for improving MetS. Furthermore, recent progress in research on brown and beige adipocytes has been remarkable, and existence of UCP1 independent nonshivering heat and signaling pathways that exclude β3-ARs have been demonstrated. The significance of using brown and beige adipocytes in metabolic syndrome treatment is expected to intensify in the future. We look forward to further research on brown and beige adipocytes.
