Shoppers pay up to 35 per cent more for frozen packaged fish compared to the fresh product found in the deli, consumer group Choice says.

The group reviewed 101 frozen fish products in the $211.5M industry and compared price and fish content as well as nutrients found in supermarket freezers.

Of the battered, crumbed and seasoned white fish products, Pacific West's Fish Fillets in a Parsley Crumb had the lowest fish content with 45 per cent fish.

I&J Flame Grills (Garlic & Parmesan and Lemon Pepper & Garlic varieties) had the highest fish content at 84 per cent. All plain, uncoated fillets and seasoned salmon fillets contained 90 per cent or more fish.

"Many frozen fish products are as much batter, crumbs and other coating ingredients as they are fish," Choice spokeswoman Ingrid Just said.

"The more fish in a product, the more of the beneficial nutrients of fish you'll be getting, so it pays to check the fish percentage in the ingredients label."

Choice says that while frozen fish products offer convenience, unit pricing shows they can be a lot more expensive than fresh fish.

For example, shoppers paid $10.99 for a 250g pack of Woolworths Select Lemon & Dill Salmon Fillets (or $43.96 per kg).

By comparison, fresh boned and skinned Tasmanian Atlantic Salmon fillets from the same supermarket's deli cost $28.99 per kg.

"While keeping a packet of fillets or fish fingers in the freezer makes life easier, you can save by buying fresh fish and making your own sauce using a handful of inexpensive pantry ingredients," Ms Just said.

Choice says nutrition claims on many fish products claiming to be a "source of" or "rich in" omega-3 can also be confusing.

The Government's National Health & Medical Research Council suggests a dietary target for long chain omega-3 fatty acids of 610mg per day for men and 430mg per day for women.

However, only 15 products in the review had 430mg or more of omega-3 per serving.

"You'd need to eat much more than a serve of many of these frozen fish products to achieve your daily target," Ms Just said.

"For example, men would have to eat 16 Birds Eye Fish Fingers and women 11 to reach that target, despite the product's claim to be a 'good source of omega-3'."

Source: News.com.au