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Introduction

With the continued rise of veganism, diets like the pescatarian diet are being slightly left behind. There was a time when the pescatarian diet was just seen as a variation of vegetarianism, but now it is seen by many vegetarians and vegans as non-vegetarian. But what exactly is the pescatarian diet, and how effective is it? In this article we will explore what it is and how it works and help you to decide whether the pescatarian diet is for you.

What Is The Pescatarian Diet?

Pescatarian (also spelled Pescetarian because the nutrition world love to make things difficult) is a portmanteau of ‘Pesce’ meaning fish and vegetarian. The term appears to have been invented in the early 90s, before that, people who ate vegetables and fish would have been classed as vegetarians. Today, this seems fairly crazy as there is nothing vegetarian about eating fish. But the diet is still popular, with many celebrities following it.

The diet is very similar to the Mediterranean diet, in that it contains a mix of seafood, oily fish, vegetables, nuts, and oils (as well as fruit). However, the obvious difference is that the Mediterranean diet contains meat while the pescatarian diet does not. Another similar diet would be the Japanese diet, where fish, rice, and vegetables make up the majority.

Both the Mediterranean and Japanese diets are considered the healthiest diets in the world, and there are several other examples of pescatarian diets around the globe. Mostly in coastal villages where the diet suits the local landscape.

In other countries, the pescatarian diet is often taken for either health, environmental, or moral reasons. By people who want to avoid meat, but still want a decent protein source. The pescatarian diet is obviously less restrictive than vegetarian or vegan diets, and the less restrictive a diet is, the easier it is to avoid deficiencies (though a lot of that is down to the individual following the diet).

What Foods Can You Eat?

There are two types of pescatarian. Those that eat dairy and eggs, and those that do not. Obviously, these are two very different diets, as a pescatarian that avoids dairy and eggs is going to be a lot more restricted in what foods they can eat. Let’s quickly look at these foods before concentrating on the foods that both forms of pescatarian can eat.

  • Milk
  • Butter
  • Eggs
  • Yoghurt
  • Cheese
  • Cottage Cheese

These foods are great sources of protein, healthy fats, vitamin D, calcium, and an amino acid called tryptophan which can help you to sleep better. It is possible to get all of these macro and micronutrients from alternative foods, but it is more difficult.

Okay, now we have examined the foods available to pescatarians who eat dairy and eggs let’s take a look at the foods available to all pescatarians.

  • Shellfish – crab, lobster, mussels, shrimp, clams etc.
  • White Fish – Cod, haddock, pollock, plaice
  • Oily Fish – Salmon, trout, tuna, mackerel, anchovies, haddock
  • Grains – Oats, rice, quinoa, bread, pasta
  • Nuts, Seeds, Legumes
  • Fruit & Vegetables

As you can see, except for the lack of meat this diet would be completely normal. Without the fish and seafood, it would be a completely normal vegetarian or vegan (if dairy and eggs were avoided) diet. This is a big positive for the diet, the more options you have the easier a diet is to follow.

Benefits Of The Pescatarian Diet

There are many benefits to following the pescatarian diet, both practical and health related. Of course, as with any diet, the pescatarian diet is only as healthy as you allow it to be. If you are following the diet but consuming 1000+ more calories than you are supposed to then the diet will be unhealthy. If you overindulge in junk food, then the diet will also be unhealthy. However, if you follow the diet correctly you should experience the following benefits.

The Pescatarian Diet Is High In Omega 3 Fatty Acids

Some white fish and oily fish in particular are excellent sources of omega 3 fatty acids, a form of fat that has many health benefits. Studies have shown that increasing your omega 3 intake can significantly reduce depressive symptoms in people suffering from depression.

A 2012 meta-analysis published in the Journal of Clinical Psychology found that omega 3 was an effective treatment for depressive symptoms in people with bipolar disorder [1].

Studies have also linked omega 3 with reduced blood pressure, lowered triglycerides, and an increase in HDL (good) cholesterol levels [2]. Omega 3 has also been linked with a reduction in inflammation and a potential reduction in cortisol (known by many as the stress hormone).

The Pescatarian Diet Contains High Levels Of Vitamin D

As well as being high in omega 3 fatty acids, oily fish is also an excellent source of vitamin D. Possibly one reason why so many Scandinavian diets contain a lot of oily fish as the people there would receive less vitamin D from the sun during the winter months.

Topping up your vitamin D levels through diet has many benefits, particularly if you live in an area that has low sunlight for large parts of the year (UK, northern US states, Canada etc). Vitamin D has been shown to reduce the risk of certain diseases and lowers the risk of colorectal cancer [3].

Vitamin D may also help to reduce body fat in overweight or obese people (who tend to be more at risk of deficiency) and it may even help you live longer. People with higher vitamin D levels appear to die at an older age, and are less likely to die from falling, cardiovascular disease, and several other causes of dying young [4].

The Pescatarian Diet Can Reduce The Risk Of Cardiovascular Disease

Due to the high amounts of omega 3 fatty acids and vitamin D found in fish, the pescatarian diet is great for improving your heart health. By removing red meat from your diet you are also slightly reducing your risk of heart disease.

A 1998 study by Key et al compared vegetarian and non-vegetarian diets [5]. The study found that pescatarians and people who rarely ate meat were significantly less likely to die from heart disease than meat eaters.

Of course, the link between meat and heart disease is almost certainly correlation rather than causation. People who regularly eat meat are more likely to also drink more alcohol, smoke more, and overeat – because most people who don’t eat meat have given up to improve their health.

But that is a debate for another article. Suffice it to say that switching from a regular-meat eating diet to a pescatarian diet is statistically likely to reduce your risk of heart disease.

The Pescatarian Diet May Reduce The Risk Of Colorectal Cancers

While it has been known for quite a while that vegetarians have a lower risk of colorectal cancer than regular meat eaters, studies appear to show that pescatarian diets are even more effective than vegetarian.

Orlich et al (2015) found that “Vegetarian diets are associated with an overall lower incidence of colorectal cancers. Pescovegetarians in particular have a much lower risk compared to non-vegetarians.” [6].

This is probably due to the higher intake of omega 3 fatty acids and vitamin D, both of which can lower inflammation – a potential cause of colorectal cancers.

The Pescatarian Diet Is High In Protein

While a pescatarian would struggle to hit the same protein targets as a non-vegetarian due to the lack of meat, they can still get a lot of protein from fish and shellfish. If they also consume dairy and eggs, then that is even more potential protein available to them.

There are many benefits to increasing your protein intake, particularly if your previous protein intake was lower than required. Increased muscle mass, recovery, and strength if you strength train. A small increase in metabolism (protein is the hardest macro for the body to break down), and the preservation of muscle while in a calorie deficit – if you are dieting.

Higher protein intake can also increase satiety (how full you feel after eating), which can prevent snacking or overeating. Of course, there are plenty of vegetarian and vegan friendly protein sources, but meat, fish, and dairy are without question the easiest sources of protein.

The pescatarian can offer all the benefits of a vegetarian or vegan diet with the benefits of a high protein diet. Which is a seriously good combination.

The Pescatarian Diet Can Reduce The Risk Of Type II Diabetes

Vegetarian and vegan diets are associated with significantly lower rates of type II diabetes, this is partly due to these diets often containing less calories (meaning less overeating which can cause many metabolic conditions), and partly due to their anti-inflammatory properties.

A pescatarian diet may even have a slight advantage over vegetarian and vegan diets for people who already have diabetes as both vegetarian and vegan diets tend to have higher carbohydrate intake, while pescatarian diets tend to have higher protein. Carbohydrates can increase blood glucose levels more than protein [7].

As we have mentioned numerous times though, just because you are following a certain type of diet, it does not mean that you can’t increase protein, lower carbohydrates (or vice versa). Some diets just make it easier to do so.

The Pescatarian Diet Can Reduce Inflammation

This has been covered in many of the previous benefits mentioned in this article, so we’ll keep it brief. Many of the foods that traditionally make up the pescatarian diet are excellent at reducing inflammation. This has many benefits across the body. Improving mood and cognition, reducing certain conditions such as arthritis, and preventing certain cancers.

The Pescatarian Diet Can Help With Weight Loss

There are several reasons why the pescatarian diet can help you to lose weight, and as mentioned before this is not a guarantee. You could eat twice as much food as usual and end up gaining weight. When calories are matched, all diets produce the same fat loss results.

But the pescatarian diet helps to increase protein, reduce high-calorie, high-fat foods, and contains omega 3 fatty acids and vitamin D which have both been associated with weight loss. A 2006 study by Rosell et al looked at the effect of diet on weight gain during a 5-year period [8]. The study found that the lowest weight gain was seen in people who had switched from a regular-meat eating diet to any diet that contained less (pescatarian, vegetarian, vegan).

The Pescatarian Diet Is More Sustainable For The Environment

Fish based diets have a much smaller carbon footprint than diets that include meat – particularly beef. While eating fish is still less sustainable for the environment than vegetarian or vegan diets, it is a big step in the right direction.

Downsides Of The Pescatarian Diet

Sadly, it is not all good news. There are several downsides to the pescatarian diet (just like with any diet).

The Pescatarian Diet Is More Restrictive Than A Non-Vegetarian Diet

While nowhere near as restrictive as a vegan diet, the pescatarian diet is still more restrictive than a non-vegetarian diet. There will be foods that you can’t eat, meals that your friends cook that you will have to skip, you’ll spend longer checking the menus at restaurants.

Restriction can be a good thing, it’s why switching diets can often lead to weight loss, because there is literally less food available for you to eat. But it can also make things more difficult. Luckily, the pescatarian diet is nowhere near as restrictive as veganism. In fact, it might be a good stepping stone from non-vegetarian to vegetarian then vegan.

Fish Contain Mercury

While mercury poisoning is rare, it does happen. Often it is highest in populations who eat the most fish. Mercury poisoning can lead to muscle weakness, neurological issues, coordination problems, kidney problems, and it can even lower intelligence.

Because of this, many nutritional bodies tend to advice limiting your fish intake to a couple of meals per week. This is problematic for a pescatarian, particularly one who is looking to build or maintain muscle and therefore needs a lot of protein.

Luckily, not all fish are equal when it comes to mercury content. While shark meat, swordfish, or king mackerel contain high levels of mercury. Salmon, sardines, shellfish, pollock, trout, and tuna contain low to very-low levels.

It is generally accepted that the health benefits of eating fish vastly outweigh any potential dangers, but definitely limit your shark intake!

Conclusion: Is The Pescatarian Diet Worth It?

There are many reasons why people follow a certain diet. Moral, environmental, health, or (most commonly) for fat loss. The pescatarian diet can be justified for any of these reasons. However, there are also other ways to achieve these goals.

If you are thinking of doing the pescatarian diet for moral reasons, then it’s a great start. No animals are harmed in the process, but obviously fish and shellfish are. Whether a fish feels or registers pain in the same way that an animal or human would is a matter for debate. Most non-vegetarians would argue that they don’t, but a vegan might think otherwise.

If you are embarking on the pescatarian diet for environmental reasons, then you will be pleased to know that it is much more environmentally friendly than a meat-filled diet. Fish do not create anywhere near as much greenhouse emissions as animals, they do not use drinking water, nor do they involve tearing down large swathes of the rainforest.

Fishing nets and fish farms do cause environmental damage though, so it is not perfect. Try to vary your fish intake and eat less common fish whenever possible.

In some ways the pescatarian diet is the healthiest diet you could look for. It is very similar to the Mediterranean diet (the gold standard of diets) but replaces all meat with slightly more fish and vegetables. There is a lot of protein, a lot of healthy fats, lots of fruit and vegetables, meaning lots of micronutrients. This diet ticks a lot of boxes.

For fat loss, the pescatarian diet is as good as any. But this is mainly because fat loss is not so much about what you eat, but how much. Provided you are in a calorie deficit (consuming less calories than you are expending) it really doesn’t matter what diet you are following. You can lose fat on a keto diet, a fasting diet, a vegan diet, a high-meat diet, whatever.

Overall, we’d say that the pescatarian diet is a fantastic diet choice, and that following it properly will yield excellent results. Make sure that you avoid high-mercury fish, that you are getting enough protein, and that you are enjoying the diet. If you are not, then ditch it for something that suits you better. All diets can be made to suit your needs.

Matthew Smith, BSc
Matthew Smith, BSc
Staff Writer & Fact Checker at DietProbe
Matthew Smith is a qualified sports scientist and registered exercise professional. He's a fitness and nutrition enthusiast and has a background in coaching and personal training.
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Fact Checked


This article has been reviewed and fact-checked by a certified nutritionist, and only uses information from credible academic sources.