Sustainable Eating: Which Diet is Best for Me?

I love my food and let’s be honest, who doesn’t? But with global warming and environmental sustainability at the forefront of our minds, knowing which diet is the best option can be a bit of a minefield. What’s more, it’s no longer a choice between just vegetarian and meat-eater - vegan, pescatarian and flexitarian have also been thrown into the mix to make the choice even more baffling. The human population is higher than it has ever been, meaning that along with avoiding a climate crisis, we also need to figure out a sustainable way of feeding the growing population and solving world hunger – not much to ask right? With these big problems in mind, I set out to provide you with the information you need to make informed decisions about the food choices you make and the impact they will have on the sustainability of our environment and our growing human population.


Meat-based diet

The traditional meat-based diet is a popular choice, and with more and more countries becoming more economically developed, the demand is ever increasing. However, this poses many problems for our fragile environment. Livestock production is a significant contributor to the warming of our environment, the methane produced by ruminants is a greenhouse gas and has a global warming potential 3.7 times higher than that of CO₂, emphasising how big of an impact dietary changes could make. Further to this, livestock rearing is a less efficient use of land than crop production. It takes tonnes of crops and water to feed livestock but these crops could be used directly to feed humans -  you can feed significantly fewer people from a field of livestock than you can with crops, so when also factoring in the task of feeding the world, plant-based diets may be the way forward.



Vegetarianism is quickly becoming more popular and seems especially popular among students, whether this be to save money, the planet, animals, for health reasons or to reduce the risk of food poisoning in grubby student kitchens with amateur chefs. Whatever the reason, it is a great option in order to do our bit to reduce climate change. Vegetarianism isn’t, however, without its downfalls. Despite plants being a tool to mitigate global warming (plants take in the harmful CO₂ from our atmosphere and produce oxygen) and producing large crop quantities from land, there is one aspect in which it is flawed. Plants require nutrients to grow, however, in many locations the land is not nutrient-rich enough to support crop growth. In these areas, the most efficient land use option would be to grow grass and rear livestock off this grass – this way the land space is not wasted and food can still be produced from it. In addition, crop growth faces challenges of its own and having spent a lot of time working on a potato farm, I’ve seen the extent of this. Producing large crop yields requires fertilisers to provide optimal levels of nutrients, pesticides to target crop pests that may otherwise damage the crops making them inedible, and herbicides to target weeds and other plants that would compete with the crops for the water and nutrients within the soil. All of the above treatments tend to be applied in a chemical form which can be detrimental to the surrounding ecosystems. When rainwater washes the chemicals into rivers and streams it can trigger a process called eutrophication which can change the ecosystem structure in a way that destroys the aquatic communities within it. Herbicides and pesticides can also disrupt the balance of the surrounding ecosystems. Killing off unwanted animals and plants can take away vital food sources for other organisms leading to unintended species declines. In addition to this, pesticides may not only kill the intended pest but also the pollinators that are vital to the success of the crop.

Of course, the issue of chemical application isn’t something that can’t be solved through changing our dietary preferences, this is an issue that lies in the hands of scientists and agriculturalists to solve. One possibility is utilising natural plant pesticide mechanism instead of chemical applications. Another involves changing the way we farm form being monocultures (one crop) to also having ‘wild’ areas that attract the predators of pests instead of having to use pesticides, and that contribute to a more diverse ecosystem, which would result in more nutrient-rich soil taking the pressure of fertilisers.


There are many benefits to be had from taking up a vegan diet, many of which are parallel to the reasons for going vegetarian however with the difference that vegans consume no meat-based products at all. Often the reason for this is to prevent animal suffering as a result of farming practices but sustainability wise it’s extremely good for our environment as it reduces the animal product demand meaning fewer animals will need to be farmed and as a result less will need to be fed (so crops can be used to feed humans) and in addition greenhouse gas emission will be significantly reduced. As with vegetarianism, even vegan food production practices aren’t perfect, they face the same issues as growing crops such as chemical application leakage into the environment, so there are still a lot of improvements to be made within the food production industry.



Pescetarianism is an option that’s been around for a long time. Many people go for this for health benefits and to reduce meat intake for environmental reasons or for animal welfare reasons under the belief that fish are less sentient animals. However, the issues that come with a pescatarian diet are a whole new kettle of fish (sorry I couldn’t resist!). Firstly, overfishing is a serious concern right now, fish populations are being depleted at a rate faster than they can recover from. In addition, many of the fishing methods are destructive to the marine habitat, destroying coral reefs and disrupting the fragile marine ecosystems. Bycatch is a further issue in which sea birds dive after the fishing hooks and get caught as a result but to reduce the impact of this bird scarers are now being deployed. It’s not just the immediate impact of fishing that is damaging our ocean ecosystems however, old fishing equipment sometimes gets lost at sea so continues to catch fish for years to come without humans ever gaining the benefit and to make matters worse, the fishing industry is a large contributor to ocean pollution which is a big concern at present.

Another fishing technique is dynamite fishing, the problem with this is that it destroys the ecosystem, and many other non-target species along with the target fish. To supply the world’s fish demand there has been a rapid increase in aquaculture practices of recent years which encompasses many of the issues that also revolve around agriculture. Fish farms also release chemical pesticides and antibiotics into the water which can harm the natural ecosystems. The significant environmental benefit of pescetarianism is that it produces significantly less greenhouse gas emissions than other animal products and in addition, fish are very healthy and a good source of nutrients and choosing a pescatarian diet takes more pressure off the other meat-based products. Making fishing processes sustainable is a big task, but being aware of the issues is the first step to overcoming them. If fishing can be managed sustainably and everyone in the industry can get on board with sustainable regulations then fish as a source of meat as a pose to other livestock could vastly improve the environmental impacts of the food industry.


A diet choice that has only recently been given a label is flexitarian, this option involves eating all kinds of meat, but only in moderation. This option is probably the most achievable for most people as it doesn’t involve restricting yourself. Substituting meat for tasty vegetarian alternatives can reduce meat demand and significantly reduce the damage livestock farming has on the environment. In addition, cutting down our meat intake yet not cutting it out entirely makes our land use more sustainable. All the land that is nutrient-rich enough and has the right conditions can be used to grow crops and vegetables and these can feed more people per hectare than livestock. Any land that cannot support plants besides grass can be used to rear livestock that can then supplement our diet as ‘treat’ items which means we will appreciate them all the more. In addition, it’s not just about how much meat you eat, you can also make a big impact by carefully choosing which meat you eat. Substituting pork and poultry for beef and mutton can reduce the environmental impact greatly as rearing this type of livestock produces significantly fewer greenhouse gases. What’s more, a flexitarian diet provides a balanced diet and offers up one of the healthiest options, you still have the vital nutrients from the meat however don’t consume so much of it that it poses other risks to your health.


So what’s right for me?

To conclude, finding the right diet is all about what works for you and your lifestyle but it is important to keep in mind the impact that the food you choose to consume has on our fragile earth. All food production comes with negative impacts and to a certain extent its part of life’s natural cycle, all organisms utilise earth’s resources and change their environments, however wherever we can, it is crucial to minimise the negative effects we have in order to conserve our beautiful planet and all the glorious animals it is home to. Minimising and mitigating the negative impacts should involve switching to renewable energy not just for farming machinery but wherever possible, as this is another reason why agriculture is a large contributor to the current climate crisis. Sustainable ways to feed the world could be met by modern and innovative solutions such as vertical farming and potentially controlled and tested GM technology. These should not be looked upon with fear but with hope for more sustainable solutions that will fulfil human needs without overexploiting the resources around us. Diet choice should no longer be focused on convenience and mass production but instead maintenance of our delicate ecosystems and sustainability of production, both to provide for the growing population and to be able to preserve the beautiful planet we have lived in for so long for the future generations that are at risk of missing out if we don’t decide on change now. Something as simple as just cutting down on meat intake or swapping your choice of meat, if taken on board by enough people, can have the power to make a change.


This article is part of HC Bristol's Sustainability themed week.