This study aimed to assess the effects of varying dietary energy and protein levels on growth-related gene expression and intestinal morphology in Hubbard broilers. A total of 234 one-day-old chicks were used and divided into six groups, with 39 chicks per group. Group I: Received a basal diet containing standard energy and protein. Group II: Received a diet with standard protein and 10% reduced energy. Group III: Received a diet with standard protein and 20% reduced energy. Group IV: Received a diet with standard energy and 10% reduced protein. Group V: Received a diet with standard energy and 20% reduced protein. Group VI: Received a diet with 20% reduced energy and 10% reduced protein. Gene expression of IGF1, Myostatin, and Ghrelin was measured. Histological and morphometric analyses of the intestines were also conducted. The results revealed that IGF1 gene expression was downregulated in all groups, except for group IV, which showed no significant change compared to the control group. Group III and group VI exhibited the lowest IGF1 expression. For Myostatin, the highest expression levels were observed in group III and group VI, while group IV showed no significant difference (p<0.05) compared to the control group. Ghrelin gene expression was significantly upregulated in all groups, with the highest upregulation seen in group III and group VI. Regarding intestinal histomorphology, all groups showed a significant decrease in villi length compared to the control group. The jejunal crypt depth was significantly reduced (p<0.05) in the group III and group VI. In conclusion, low energy had a more pronounced effect on the expression of growth-related genes and intestinal indices than low protein.