Tuna (frozen)

Why tuna (frozen) is rated low

Frozen tuna is low FODMAP. Tuna is a plain fish made of protein and fat with negligible carbohydrate, and freezing adds nothing to it, so the rating, which is estimated from what the fish is made of rather than from a measured serving, lands low. The serving data lists a single rung, "Any typical portion", and it reads low. The catch is that frozen tuna is often sold seasoned, marinated or crumbed, and those additions are not covered by the rating for the fish itself.

What changes your risk

• Marinades and seasoning packs Pre-marinated steaks and poke-style cubes can carry garlic, onion, honey or a sauce base you cannot see. Plain frozen tuna should list tuna and little else on the label.
• Crumbs and batter Frozen tuna fingers and crumbed steaks are coated in wheat crumbs, which are not low FODMAP.
• Freezing and thawing Freezing neither adds nor removes FODMAPs, so thawed plain tuna rates the same as fresh.
• The meal around it Low is per serving, not per meal. A tuna pasta bake with wheat pasta and a milk sauce, or a poke bowl topped with onion, builds a high load around a low fish.
• Portion The rating covers any typical portion. A very large helping sits outside what the estimate describes.

What else works

Fresh tuna, salmon, cod, prawns and plain canned tuna in spring water or oil all sit in the same low place for the same reason. The versions that are not reliably low are tuna salad mixed with onion or celery, tuna mornay made with ordinary milk and cheese sauce, canned tuna in flavoured sauces that list onion or garlic, and crumbed tuna products. For flavour, lean on lemon juice, garlic-infused oil, chives and the green tops of spring onions.

How to keep it low

Thaw frozen tuna overnight in the fridge, or seal it in a bag and set it in cold water, then pat it dry so it sears rather than steams. Tuna steaks cook fast in a hot pan with garlic-infused oil, salt and pepper, finished with lemon juice. When buying, choose bags with a single-ingredient label and treat anything sold as marinated or seasoned as a separate product to check. Freezing steaks individually means you only thaw what one meal needs, and serving them with rice, potato, bok choy or green beans keeps the whole plate low.

Common questions

is frozen tuna low fodmap

Yes. Plain frozen tuna is rated low FODMAP, estimated from what it is made of: fish protein and fat with negligible carbohydrate. The serving data reads low at "Any typical portion".

how much tuna is low fodmap

The serving data gives one rung, "Any typical portion", and it reads low. Very large helpings are not covered by the estimate.

is canned tuna low fodmap too

Plain canned tuna in spring water or oil is the same fish made of the same things. Flavoured canned tuna is a different story, since many of those sauces contain onion or garlic, so check the label.

can i eat a tuna poke bowl on low fodmap

The tuna is low, but poke bowls are often topped with onion and dressed in garlic-based sauces. Ask for the onion left off and build it with rice, cucumber and carrot instead.