This study explored the effects of dietary chicken protein at high (HCK, 40 % E) or normal (CK, 20 % E) levels on obesity development of rats fed high-fat diets. Compared with the CK diet, the HCK diet reduced body weight gain (by 15 %), epididymal adipose tissue mass (by 18.4 %), and adipocyte size (by 18.8 %) significantly without affecting the food intake of rats. It also reduced blood insulin and glycosylated serum protein (GSP) significantly by 45.4 % and 14.3 %, respectively; however, the OGTT and HOMA-IR results were not different. The HCK diet downregulated EAT transcriptomics related to the biosynthesis of cholesterol, triglycerides, and fatty acids, which were highly correlated with the most downregulated hub genes, Insig1, Srebf2, Hmgcs1, and Fasn. Therefore, high dietary chicken protein content reduced body fat accumulation, blood insulin, and GSP, and downregulated EAT transcriptomics related to lipid biosynthesis in rats fed high-fat diets.