When making Gravlax, a mixture of sugar and salt is used to coat the fish and cure it. After the curing time has passed, the curing mixture is washed off together with any spices used and the excess fluids secreted from the fish.
Does the sugar penetrate the fish and add to the caloric value of the final product, or is it used only to draw fluids away and is all washed away? And if yes, to what extent?
A similar question goes about the salt and sodium content of the final product.