What we found

Most products we looked at were single-serve. We were looking for those that were low in fat (especially saturated fat) and sodium. For full details of all the canned fish we looked at, see Products compared.

Plenty of low-fat choice

All products labelled "lite" or "98 percent fat free" were good low-fat choices, though some exceeded our criteria for sodium. Only 7 of the 56 products we surveyed exceeded our criteria for saturated fat (more than 2g per 100g).

The healthier options aren't limited to products labelled "lite" or "98 percent fat free". Several of our recommended products were "regular" products.

Check the label

Don't rely on a particular brand or flavour as a guide to a healthy choice. Sodium and fat content varied within brands and flavours. For instance, Sealord's Tuna Sensations Smoked Flavour contained 18.5g of fat per 100g - that's 11 times more fat than Sealord's Tuna Lite Lightly Smoked Flavour.

Hold the salt

The Ministry of Health recommends a range of daily sodium intakes. The maximum daily amount that adults can consume without increasing their risk of high blood pressure is 2300mg. But a mere 920mg is adequate for good health.

Two sweet Thai chilli-flavoured products approached the sodium barrier: Pams Tuna Sweet Thai Chilli and Pacific Crown Tuna Sweet Thai Chilli & Lime. Both contained more than 1000mg of sodium per 100g. If you eat the whole can in one go (and it's small so you probably would) then you'll be getting nearly half your daily maximum in one hit. Choose flavours that contain less than 400mg of sodium per 100g.

Tip: If your favourite flavour is high in sodium, don't eat it with other high-sodium foods like salty crackers and limit the amount you eat.

Flavoured fish or fish flavoured?

Almost all the products we looked at had their percentage of fish listed on the label. The highest fish content was 99 percent for Sealord Red Salmon; the lowest was a miserly 45 percent (Sealord Tuna Lite Mexican Salsa).

One to watch: Sealord's Tuna Sensations Tuna Spread contains only 23 percent tuna. Yes, it is labelled as a "tuna spread". But it sits alongside the canned tuna products on the supermarket shelf and it'd be easy to think it was more than a spread - so don't get caught out. This product is also high in both sodium and fat.

Tip: Always read the ingredients list. Look for products which contain at least 50 percent fish - more fish means more protein.

Chicken in a can

If you're looking for a convenient source of protein and don't like fish, a product like Chop Chop! chicken could be the answer. The sodium and fat content of the chicken chunks in spring water and sea salt are similar to that of tuna canned in brine. But canned chicken won't provide you with the omega-3s found in canned fish.