Two thirds of us eat fish less often than the recommended twice a week, according to a YouGov survey we commissioned earlier this year.

Of those surveyed, over-55s ate the most fish, with 45 per cent consuming at least two portions a week. Young families with children aged between five and 11 ate the least, with only 25 per cent consuming fish twice a week.

Fish and shellfish are good sources of vitamins and minerals and are often lower in fat than meat. Oily fish is particularly high in omega-3 fatty acids, which have benefits for the heart and brain, and in vitamin D, which is needed for healthy bones. People who regularly eat fish tend to eat less red meat, which helps to reduce the risk of bowel cancer and heart disease.

As part of a healthy diet, we should eat at least two portions (140g each) of fish a week, including one of oily fish such as salmon, trout, fresh tuna, mackerel or sardines.

However, despite the benefits, government figures show that our overall consumption of seafood has declined in the past ten years.

Oily fish

Oily fish is rich in long-chain omega-3 fatty acids, which are thought to help prevent heart disease, and are critical for babies’ nervous systems to develop properly.

Oily fish is also a good source of vitamin D and some, like whitebait, tinned salmon, sardines and pilchards, also contain small edible bones that provide calcium and phosphorus, which are also needed for bone health. Tinned tuna doesn’t count as an oily fish because a lot of the oil is lost during processing.

Because oily fish can contain low levels of pollutants, the advice is to eat no more than four portions of it each week. For women who are pregnant, trying to conceive or are breastfeeding, the advice is a maximum of two portions a week.

Swordfish (plus two types of white fish – shark and marlin) contains more mercury than other types of fish, so all people are advised to eat no more than one portion a week. These fish should be avoided completely if you’re a child or a woman who is pregnant or trying to conceive.

White fish

White fish includes cod and haddock, but also more sustainable species such as pollock, basa, hake and tilapia. Most white fish is safe to eat as often as you like.

Anyone who eats a lot of fish, or is pregnant, trying for a baby or breastfeeding, should check with their GP or NHS Choices for full details of the current advice.

How can you encourage people to eat more fish?

The cost of fish is often given as a reason for avoiding it but tinned and frozen fish can be great value options. Some people may not know how to cook fish – signpost them to our website for some simple fish recipes. Read our blog post about how to encourage children to eat more fish.