Fish have long been a darling of the diet world. Salmon, cod and sea bass are praised for being a filling yet low-fat source of protein and are recommended by nutritionists around the world.
The NHS recommends that we eat at least two servings per week to reach our quota of omega-3 fats, which are beneficial for heart and brain health.
But are some types better than others? Yes, according to dietitians.
Speaking to the Daily Mail, experts revealed that some types contain much less fat and are therefore better for people looking to lose pounds. Others, meanwhile, can even be harmful if eaten regularly.
Some species, like mackerel for example, contain much higher amounts of essential nutrients that many of us are missing, such as vitamin B12, according to dietitian Sophie Medlin, a registered dietitian and founder of City Dietitians. So what should you choose for your fish dinner?
Salmon is praised as one of the best sources of protein, but how does it compare to other fish?
Mackerel
Per typical fillet: 214 calories, 15.7 g protein, 16.8 g fat, 4.4 g saturated fat, 0.15 g salt
Mackerel is a fast-swimming, oily fish found along the British and European coasts and belongs to the same Scombridae family as tuna. EExperts say it is one of the healthiest fish to eat.
Its top quality is its abundance of omega-3 fatty acids – more than any other fish and almost twice as much as you’ll find in an average salmon fillet.
An extensive Harvard study published in the early 1990s found that eating two mackerel fillets per week could reduce the risk of death from heart attack by 36 percent.
Ms Medlin points out that mackerel, like salmon, is high in fat. And unlike other fish, a significant portion – about a third – is made up of saturated fat, the type that can damage blood vessels.
However, this is still less than a quarter of a woman’s daily limit and a fifth of a man’s, meaning that for most people, the fat is worth the benefits.
Verdict: 4.5/5
Cod
Per typical fillet: 112 calories, 25.1 g protein, 1.3 g fat, 0.35 g salt
A bottom-dwelling fish with white, flaky flesh that is often a favorite for fish and chips. It is often imported from abroad, mainly from China, Iceland and Norway.
Experts say cod – baked or broiled rather than fried – is an excellent choice for people on a low-calorie diet who want to lose weight.
“Cod is an excellent lean protein source,” says Ms. Medlin. Cod contains roughly twice as much filling protein as mackerel, meaning the risk of feeling hungry after eating is low.
Ms Medlin adds that it also contains a uniquely high level of iodine, which is essential for nourishing the hormones that control metabolism and regulate heart rate.
It is also critical for proper brain and nervous system development during pregnancy and early childhood.
Research recently found that omega-3 supplements provide no benefits, but fish does
“The main disadvantage of cod is that it contains much less omega-3,” says Medlin. “And most people don’t get enough omega-3 in their diet.” According to the University of California Davis Department of Nutrition, it contains about ten times less than the equivalent portion of salmon.
Verdict: 4/5
Sea bass
Per typical fillet: 149 calories, 17.9 g protein, 8.4 g fat (almost completely unsaturated), 0.11 g salt
Sea bass are native to the Northeast Atlantic Ocean, the Mediterranean Sea and the Black Sea, although they sometimes occur in freshwater rivers.
If you prefer white fish to mackerel, sea bass is a good option because of its high protein and omega-3 content, says Ms Medlin.
“In general, you get more omega-3 here than with other white fish,” she adds.
However, there may be risks associated with eating sea bass several times a week. ‘Sea bass often contains more mercury than other fish such as salmon and cod,’ says Ms Medlin.
Mercury enters water through sources such as coal burning, mining, industrial processes and waste, and is then absorbed by small underwater organisms.
Fish eat these organisms, causing mercury to build up in their tissues. Certain fish – usually those that are larger and higher on the food chain – contain higher levels of spores than others.
Mackerel is the fish that contains the highest amount of brain-boosting omega-3 acids
The chemical is known to be toxic to humans at certain levels and causes problems with vision, coordination and memory.
‘The mercury content in sea bass is usually so low that you could eat it, for example, once a week,’ says Ms Medlin.
Verdict: 3/5
Salmon
Per typical fillet: 197 calories, 23.8 g protein, 11.3 g fat, 0.12 g salt
As an oily fish, salmon is high in omega-3 fatty acids, which have been linked to a lower risk of chronic disease and protecting brain cells from age-related damage.
Interestingly, studies have shown that the benefits of these fats only manifest themselves when administered through food, and not through supplements.
According to Ms Medlin, ‘salmon is an excellent all-rounder’.
‘It contains a lot of omega-3, proteins, vitamin D, B12 and selenium.’ It is estimated that up to a third of older Brits are deficient in B12 – which is essential for healthy blood flow and energy levels.
Vitamin D deficiency is also common. The nutrient is essential in helping our bones absorb strengthening calcium.
However, salmon contains roughly ten times as much fat as fresh tuna, although 80 percent of it is the unsaturated, healthier kind.
This makes it higher in calories than low-fat options such as sea bass and cod.
“But considering the extra nutrients it provides, it’s worth the extra calories,” says Ms. Medlin. For example, the protein in the fish is there all nine essential amino acids, meaning our bodies can easily use it for energy and muscle building.
Verdict: 5/5
Tuna
Per typical ‘steak’ fillet: 144 calories, 31.9 g protein, 1.6 g fat, 0.09 g salt
Tuna, large, fast-swimming marine fish found in the Indian, Pacific and Atlantic Oceans, belong to the mackerel family.
The meat is firm and dense and has a mild, savory flavor when cooked – or a rich, buttery flavor when eaten raw.
Ms. Medlin rates it lower than other fish, explaining that “although it is a lean protein sauce rich in selenium and B12, mercury contamination is a concern.”
‘Larger tuna species such as yellowfin tuna and Atlantic bluefin tuna contain particularly high levels, so we need to be aware of how much we consume on a regular basis.’
However, research shows that canned tuna contains much less mercury than fresh tuna.
Ms. Medlin adds, “As long as fresh Tuna contains some omega-3, it’s much, much less than mackerel and salmon, although slightly more than you’ll find in cod.’
Verdict: 3/5
And what about shrimp?
Per serving of king prawns: 51 calories, 11 proteins, 0.3 g fat, 1.19 g salt
Not technically a fish, but instead crustaceans and shrimp can be found in freshwater and marine waters, depending on their species.
Unlike most fish, they are also more likely to cause an allergic reaction – with between 0.5 and 2.5 percent of the population having a shellfish allergy.
Although they are a very low-calorie and low-fat choice, they contain the highest salt content of all the options analyzed.
Although a small portion makes up only one-sixth of your daily salt intake, this can quickly add up because you often have to eat large amounts of shrimp to feel full, experts say.
“But they do contain some omega-3, although much less than oily fish,” says Ms Medlin.
‘The problem with shrimp is that they are often served breaded or fried, which negates some of the health benefits, so make sure they are steamed.’
Verdict: 3/5
*Nutritional information sourced from tesco.com
