In the past few decades, the American pig industry has seen a steady increase in market weights. This trend is driven by economic factors at the packing plant, where fixed costs can be allocated over more pounds of pork sold per pig, and at the farm, where sow and other fixed costs can be spread over more pounds of pork sold. Unfortunately, there is very little empirical data explaining the changes in growth rate, feed intake, energy intake and feed efficiency beyond 300 lb live weight; nor is there much data on the composition of carcasses at these heavier weights. This leads to uncertainty on the impact of further increases in market weights are adopted by our industry. Understanding the growth implications of marketing heavier hogs is important, so nutritionists, meat scientists, geneticists, producers and others involved in the production chain understand what is required to achieve optimal outcomes in terms of growth performance, carcass composition and financial returns.