North American dining customers like to have a singular large piece of protein in the center of the plate. When fish is the protein of choice, the portion size from many species is limited by the overall size of the fish. Therefore, for these species, the means to achieve a singular larger portion of “center of the plate” protein is to grow a larger animal. However, fish become less efficient in converting feed to protein as they age. A second option would be to provide two smaller fillets originating from younger, more efficient fish. Here, the sustainability ramifications of these two protein provisioning strategies (single large or two small fillets) are considered for three species of fish produced in aquaculture. Growth data for channel catfish (Ictalurus punctatus) produced in ponds, rainbow trout (Oncorhynchus mykiss) in raceways, and sablefish (Anoplopoma fimbria) in marine net pens, were modeled to assess the total biomass and overall food conversion ratio for the production of small, medium or large fish. The production of small fish added an additional 50% or more biomass per year for trout, catfish, and sablefish compared to the production of large fish. Feed conversion ratios were also improved by nearly 10% for the smaller compared to larger fish of each species. Thus, even though all of these species tend to be considered aquaculture species of low environmental impact (and hence “green” or sustainable options), the product form requested by retailers and served by chefs can further increase the sustainability of these species. Full article