Since uncooked fish carries with it the risk for parasites, visit sushi restaurants that serve only previously frozen or cooked fish. A sushi chef combines pieces of fish, vegetables and sometimes mayonnaise or sauce on dried seaweed, rolls it up and cuts into pieces, usually four to six pieces per order. White rice is usual, although you may be able to find brown rice in some restaurants. Depending on the size of the roll, you’ll usually get about a half-cup to one cup of rice per roll, or one to two servings (100 calories per serving). Fish can be very lean, like abalone or flounder, or fattier (and healthy, too) such as tuna, salmon and mackerel.