With the price of corn on the rise, producers are looking for alternative feedstuffs that would allow them to finish pigs at a cheaper price. However, this would result in feeding pigs a low energy, high fiber (LEHF) diet while pigs were selected for efficiency and growth on a high energy, low fiber (HELF) diet. The objective of this experiment was to determine if pigs from a line selected for low RFI (more efficient) on a HELF diet maintained their superiority in feed intake and efficiency to pigs selected for high RFI when fed LEHF diet. The results of this study showed that pigs from the low RFI line have greater feed efficiency than pigs from the high RFI line when fed a standard HELF diet, but this difference disappeared when they were fed a LEHF diet. Diet did not affect feed intake of the low RFI pigs but resulted in a reduction in feed intake of the high RFI linewhich resulted in both lines consuming the same amount of feed on the LEHF diet. Pigs grow slower on the LEHF diet but there was no difference between lines for either diet. The results of this study suggest that, as feed costs rise and producers look more and more towards alternative feedstuffs, selection may need to be based on performance on such diets, rather than a traditional corn-soy diet.