While sushi calories may vary by their sizes, there are minimal deviations. Here is a list of an average piece of nigiri sushi and their caloric value.
Abalone Shellfish 34 cal Albacore Fish 38 cal Arc Shell Shell Fish 34 cal Crab Crustacean 35 cal Eel Fish 65 cal Egg (Non-Seafood) 40 cal Geoduck Shellfish 31 cal Gizzard Shad Fish 37 cal Halibut Fish 34 cal Mackerel Fish 40 cal Octopus Other Seafood 34 cal Red Snapper Fish 34 cal Salmon Fish 37 cal Salmon Roe 50 cal Scallop Shellfish 34 cal Sea Eel Fish 60 cal Sea Urchin Roe 40 cal Shrimp Crustacean 33 cal Spanish Mackerel Fish 36 cal Squid (Other Sea food) 35 calSweet Shrimp Crustacean 32 cal Tuna Fish 37 calTuna Belly 55 cal Yellowtail Fish 55 cal
With the exception of eel, all ingredients are very low in saturated fat. The shellfish, and white fishes have minimal amount saturated fat (as well as saturated fat), and accounts for their lower calories.
Next come the red fishes, or mainly tuna and yellow tail. Salmon, tuna belly, and the blue fishes (mackerel,gizzard shad) have higher caloric value due to their high unsaturated fat content, and they are the most beneficial fish that you can eat to maintain a healthy cardiovascular system since they lower cholesterol levels.
Sushi calories should not be given too much concern. All around, they are all healthy, if eaten moderately. An average person should be satisfied with about 10 pieces of nigiri, or 400 calories at the most.