A member of the British Dietetic Association, Juliette Kellow has worked in the NHS and for the food industry, and is the former editor of magazines Slimming and Top Santé. She's also the former editorial...

These essential fats help keep the heart, brain and eyes healthy. We compare amounts in some fish and shellfish favourites to help you get enough

The Scientific Advisory Committee on Nutrition (SACN) says we should have around 3g (3,000mg) omega-3 fats a week. Oily fish is undoubtedly the best source, and the Department of Health translates the SACN advice into eating two portions of fish a week (where a portion is around 140g cooked or 170g raw), including one oily variety. These are large portions, however, so you may need to have fish more than twice a week to meet the recommendations.

The reality is most of us fail to eat even one portion a week – on average, adults manage just one-third of a serving of oily fish a week and teenagers just one-tenth of a serving.

As our chart shows, it isn’t only oily fish that provide omega-3 fats – shellfish contain good amounts and white fish is also a source.

Some plant foods also contain omega-3s, but only fish has the ‘ready made’ long-chain type that’s thought to be most beneficial to our health. For this reason, vegetarians may want to consider a supplement.

Omega-3 values shown are per 100g raw fish unless otherwise stated

Cod, 70mg

Fresh tuna, 80mg

King prawns, 110mg

Plaice, 160mg

Squid, 400mg

Mussels (boiled), 570mg

Brown and white crabmeat (boiled), 585mg

Rainbow trout, 1,030mg

Sardines, 1,110mg

Seabass, 1,200mg

Farmed salmon, 2,210mg

Mackerel, 2,600mg

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