The global food system is facing the challenge of producing sufficient nutrients to accommodate future demands within planetary boundaries, while reducing malnutrition. Although nutrient-rich seafood can play a prominent role in resolving this challenge, seafood from capture fisheries is currently partly wasted. Here we quantified the nutrient contribution from capture fisheries through a hypothetical scenario that assumed all captured seafood and byproducts from seafood processing would be used for human consumption. Our simulations show that available seafood per capita can be doubled without increasing the pressure on global fisheries when all reported, illegal, and discarded capture is used as food, complemented with processing byproducts. In such a scenario, seafood contributes greatly to daily nutrient requirements – e.g., omega-3 can be fully met. Although uncertainty should be considered, these results indicate that putting the whole fish on the table can increase nutrient availability from capture fisheries substantially and sustainably.