Tuna, yellowfin, cooked (dry heat)

Fresh yellowfin tuna, cooked by dry heat (grilled, broiled, or seared), is USDA FoodData Central's FDC ID 172006 (SR Legacy): 29.2 g protein and 130 kcal per 100 g, or 22.46 g protein per 100 kcal — (29.2 / 130) x 100. A 3 oz (85 g) cooked tuna steak, a standard restaurant/dietary-reference portion, supplies about 24.8 g protein for 110.5 kcal. Tuna is notably rich in vitamin B12 (2.35 mcg per 100 g, near the full 2.4 mcg/day adult requirement cited by MedlinePlus in one serving) and selenium (108 mcg per 100 g), alongside 47 mg cholesterol, 54 mg sodium, and only 0.205 g saturated fat per 100 g (all per FDC). The most important caution for tuna is mercury, and it depends on which tuna: the FDA/EPA fish-consumption advisory places "Tuna, yellowfin" specifically in its middle "Good Choice" tier (moderate mercury) — a different, more cautious category than canned light/skipjack tuna, which the same FDA chart lists as a lower-mercury "Best Choice." That distinction matters in practice: pregnant people, those who may become pregnant, and young children are advised by the FDA to limit "Good Choice" fish like fresh yellowfin/ahi tuna to about one serving a week, whereas canned light tuna can be eaten more often. General adult guidance from Harvard's Nutrition Source notes evidence for mercury harm at typical adult consumption levels is "limited and conflicting," and weighs that against fish's documented cardiovascular benefits, but does not blanket-clear high-mercury species. Fresh or frozen yellowfin (often labeled "ahi") tuna steaks are sold at most supermarket seafood counters and specialty fish markets in the US, typically priced higher than canned tuna or whitefish like cod or tilapia. Because of the mercury tier difference, shoppers substituting canned tuna for a fresh yellowfin steak should not assume identical mercury exposure even though the protein density is comparable.