Which Foods Pack the Biggest Nutritional Punch?

Tuna

1st place: Canned Tuna
2nd place: Sushi-Grade Tuna
3rd place: Tuna Steak

Of the three, a cooked tuna steak contains the most mercury per ounce, because as the meat loses water while it cooks, the neurotoxin becomes more concentrated. But sashimi isn't a great option, either. Sushi-grade tuna tend to be quite large, and the bigger the fish, the more mercury it accumulates. Go with canned chunk light, which is made from smaller species.