Pescatarian, vegetarian, or vegan? Which is better for the planet?

ZOE recently published this guide to the vegetarian diet. We explain that cutting down your meat intake can benefit the environment and your health, particularly if you focus on eating whole foods.

However, if you’ve always eaten meat, the idea of cutting back might feel daunting.

If you’re interested in the health benefits of vegetarianism but don’t feel quite ready to commit, other diets offer a little more flexibility.

What are other options?

Several eating patterns can help you reap the benefits of eating less meat.

For instance, flexitarian diets — which involve only eating meat occasionally — are becoming more popular. This way of eating may help improve your metabolic health and blood pressure.

A flexitarian approach may also help prevent diabetes, though it’s difficult to be sure, as there’s no single definition of a flexitarian diet.

Pescetarianism is another option. A pescetarian diet avoids all meat apart from fish.

Studies suggest that 17% of people who describe themselves as vegetarians are actually pescetarians. 

A pescetarian diet involves eating like a vegetarian but with added fish and seafood as a source of protein and other nutrients.

Why do people choose a pescetarian diet?

As with any dietary choice, the reasons vary. A person may want to reduce their consumption of animal products without committing to a completely plant-based diet.

The health benefits of fish and concerns about the health effects of eating meat are other reasons to switch to a pescetarian diet.

Some people avoid meat for sustainability reasons. Livestock farming is responsible for 14.5% of greenhouse gas emissions, considerable biodiversity loss, and land destruction.

There are, of course, other ethical considerations.

Some people feel more emotionally connected to other mammals, such as pigs and cows. Because they feel more distant from fish, people might be more comfortable eating these animals.

There’s a lot of debate among scientists about whether fish feel pain like other animals do. 

The journal Animal Sentience explores this topic further. If you’re interested in current research about whether different living beings can feel and think, it’s worth a look.

Interestingly, studies show that people who decide to stop eating meat for ethical reasons tend to be more committed to their choice and stick with it for longer than people who make the same decision for health reasons.

This shows the considerable impact that our moral code and social identity can have on our food choices.

Is the pescetarian diet a sustainable choice?

Many of us make decisions about what we eat based on the environmental impact of our diet. 

It’s already well-established that meat production contributes to climate change. 

A study published last month looked at the diets of over 50,000 people to assess their environmental effects, and it concluded that eating fewer animal-based foods can significantly reduce your environmental footprint.

A similar study took a more specific look at the different environmental impacts of certain diets. The scientists gave each diet a score based on its environmental effect, and a higher score meant a greater effect.

The score took greenhouse gas emissions, land usage, and energy use into account.

The researchers gave an omnivorous diet — one that contains all the food groups, including meat — a score of 0.29. 

Interestingly, vegetarian and pescetarian diets scored very similarly. The pescetarian diet scored 0.11, and the vegetarian diet scored 0.12. 

While greenhouse gas emissions were slightly higher for the pescetarian diet, the vegetarian diet scored fractionally higher for land usage. 

This suggests that there’s no significant difference in the environmental impact of pescetarian and vegetarian diets, using this scoring system.

Perhaps unsurprisingly, the vegan diet had the lowest environmental impact, with a score of 0.09. However, this score isn’t much lower than those of vegetarian and pescetarian diets. 

The biggest difference in scores was between the diet with meat and the diets without it.

These findings suggest that if you’re making decisions based on the health of the planet, then removing meat from your diet has the greatest impact.

Does fishing damage the environment?

Although the pescetarian diet seems like a relatively sustainable choice, fishing does have its own set of environmental problems. 

Overfishing and by-catch are two damaging environmental effects unique to fishing.

Overfishing involves removing too many fish from the ocean, leading to a decline in fish populations.

Humans aren’t the only species that rely on fish, and overfishing is leading to the extinction of many species of sharks and rays.

By-catch is when the fishing industry unintentionally catches other species in the sea. 

This affects a host of animals, like the harbor porpoise and many other whale and dolphin species. These mammals breed very slowly, so even a small number of deaths due to by-catch can have devastating effects on their populations.

How to prevent these environmental problems

There are more sustainable ways to enjoy fish. For example, buying a variety of fish can help prevent putting too much pressure on one species.

The Marine Conservation Society has published a Good Fish Guide. This gives each species a rating based on sustainability.

Keeping these ratings in mind can help you make more environmentally conscious decisions about which fish to buy.

Overall, no diet is perfect. The production of food affects our world in different ways. But having an awareness of specific environmental effects can help us make more informed choices. 

Is pescetarianism new?

While the concept of pescetarianism is fairly new — the word was first used in the 1990s — cultures around the world have prioritized fish as a protein source for thousands of years.

The traditional Japanese diet, called washoku, was added to UNESCO’s Intangible Cultural Heritage list in 2013. Washoku includes fish, seaweed, seasonal fruit and vegetables, green tea, and soybeans. 

Studies suggest that following this diet reduces the risk of heart disease and obesity.

Washoku also has a lower nitrogen footprint than the modern Japanese diet, so it contributes less to nitrogen pollution.

Nitrogen pollution can be caused by fertilizer use and the breakdown of animal manure. It can damage wildlife, kill fish, and fuel climate change.

So, a diet that leads to less nitrogen pollution is good news for the planet. 

What are the health benefits of pescetarianism? 

The evidence from Japan shows that a traditional diet that emphasizes fish may help protect us against some diseases.

While all diets that focus on fish are different, there may be general health benefits to eating more fish.

Regular fish consumption may help reduce inflammation, support the immune system and wound healing, and protect the nervous system.

Eating fish at least twice a week might also help protect against heart disease.

Still, a vegetarian or pescetarian diet doesn’t guarantee health benefits — if, for instance, you replace meat with highly processed foods, like french fries.

Everyone is different, but focusing on eating a range of plants and consuming less processed food can help your physical and mental health, whether you choose to eat meat, fish, or neither.


A critical review on the health benefits of fish consumption and its bioactive constituents. Food Chemistry. (2022). 

Awakening to the politics of food: Politicized diet as social identity. Appetite. (2016).

By‐catch risk for toothed whales in global small‐scale fisheries. Fish and Fisheries. (2021).

Climate change and livestock: Impacts, adaptation, and mitigation. Climate Risk Management. (2017).

Differences between health and ethical vegetarians. Strength of conviction, nutrition knowledge, dietary restriction, and duration of adherence. Appetite. (2013).

Flexitarian diets and health: A review of the evidence-based literature. Frontiers in Nutrition. (2017).

Food and agricultural organization of the United Nations. (n.d.).

Food nitrogen footprint reductions related to a balanced Japanese diet. Ambio. (2018). 

Globalization of food patterns and cardiovascular disease risk. Circulation. (2008).

Good Fish Guide. (n.d.).

Greenhouse gas emissions, energy demand and land use associated with omnivorous, pesco-vegetarian, vegetarian, and vegan diets accounting for farming practices. Sustainable Production and Consumption. (2020). 

How proximal are pescatarians to vegetarians? An investigation of dietary identity, motivation, and attitudes toward animals. Journal of Health Psychology. (2021).

Mediterranean diet and diabetes: Prevention and treatment. Nutrients. (2014).

Overfishing drives over one-third of all sharks and rays toward a global extinction crisis. Current Biology. (2021).

Porpoises, by‐catch and the ‘pinger’ conundrum. Aquatic Conservation: Marine and Freshwater Ecosystems. (2023).

Traditional Japanese diet score — association with obesity, incidence of ischemic heart disease, and healthy life expectancy in a global comparative study. The Journal of Nutrition, Health and Aging. (2019).

Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts. Nature Food. (2023).

Washoku, traditional dietary cultures of the Japanese, notably for the celebration of New Year. (2013). 

Why human pain can’t tell us whether fish feel pain. Animal Sentience. (2016).