There’s a reason a can of tuna is your go-to protein food. (And if it’s not, then maybe it should be.) Not only does one 3.5-oz serving pack 30g of lean protein, but it’s also one the easiest and most accessible fishes. Plus, tuna gives you a decent dose of potassium, B12, and selenium—an antioxidant necessary for thyroid metabolism and boosting immunity, says Robyn Youkilis, a nutritionist and healthy cooking expert.

So tuna is good for you. That’s been established. But what do you need to think about at the grocery store? Standing in a sea of cans, jars, and steaks might make your head spin, which is why we broke it down for you, by variety:

  • Packaged tuna. Holy decisions, right? Just know that picking water-packed over oil-packed tuna will save you about 2g of saturated fat, and light tuna—while less ideal flavor-wise—is lower in mercury than the darker varieties. So choose your can (or pouch or jar) accordingly.
  • Fresh tuna. For a lean but meaty meal, do not fear the tuna steak. Just make sure you’re buying fresh. You’ll want to avoid any with dark brown spots or a rainbow sheen, and the steaks should smell ocean-fresh (read: fishy but not too fishy).

Youkilis says you can safely eat tuna once or twice a week, as long as you’re not eating too many other big fish. So broaden your horizons with these six easy recipes.