do you think a sushi diet could be appropriate for a body builder looking to gain size? does it contain enough calories and protein to supply your body in a bulking process?
Sushi can be a nice way of adding variety to your meals, but I would not consider eating only sushi, and even less so as part of a healthy diet. Keep in mind that even for the Japanese sushi are an occasional meal - they don't eat only sushi.
I really like sushi but like @stevesmi said, make sure it's authentic quality sushi.
Ask the waiter what they put in the rolls. A lot of commercial sushi rolls like 'California rolls' are loaded with mayonnaise.
I personally stick with the sushi that is just a piece of fish ontop of a bed of rice. That way you know there are no fillers in it. It's called nigiri