Characterizing how selectively bred fish with improved production traits are affected by environmental factors is essential for ensuring germplasm with superior genetics perform well across different production systems with variable feeding strategies. In this study selectively bred rainbow trout (Oncorhynchus mykiss) with improved fillet yield were reared on three commercially available diets that varied primarily in dietary lipid/energy content: low lipid (LL, 18%), moderate lipid (ML, 24%), and high lipid (HL, 29 – 33%). The objective was to determine if a genotype by environment (diet) interaction affects product yield and muscle quality traits in a line of rainbow trout selected for high (HY) and low (LY) fillet yield. Main effects of genetic line (P < 0.05) were observed for fork length and viscera yield, for which the LY line was greater, and carcass yield and fillet yield that were higher in the HY line (Figure 1a,b). Muscle quality traits of fillet color, muscle cellularity (Figure 1c) and muscle firmness exhibited main effects of genetic line (P < 0.05); findings indicated selection for fillet yield did not compromise fillet quality. A genotype by diet interaction (P < 0.05) was observed for viscera lipid content at the 2 kg harvest, for which viscera lipid content was similar between the HY and LY lines for the LL and HL diet, but greater (P < 0.05) in the LY line for the ML diet (Figure 1d). Main effects of diet were consistently identified for growth, viscera yield (Figure 1a), and indices of muscle quality (P < 0.05, Figure 1e). Collectively, these findings indicate that higher product yields in the selectively bred HY line of rainbow trout will persist across diets with variable crude lipid/energy contents.