Veganism and Plant-Based Diets

See also: Ethical Food Consumption

Vegan diets—those that contain no animal products at all—seem to be everywhere these days. Wherever you look on social media, there is someone extolling their virtues, either for health or for the planet. We are encouraged to follow Veganuary (vegan January) and vegan ‘influencers’ show us beautiful plates of plant-based food.

Vegan food is also increasingly big business. The global vegan food market was valued at US$16.45 billion in 2022, and this is projected to increase on average almost 10% a year over the next ten years. However, do the benefits of a vegan diet actually stack up, either for us as individuals, or for the planet? This page examines the evidence and gaps, and aims to provide some answers to help you make up your own mind.

Defining Veganism

Veganism is defined as not consuming or using any animal products.

Vegans therefore eat no animal products (including milk, eggs and honey), and do not wear or use leather or similar goods. Veganism is also known as following a plant-based diet.

Vegetarianism is similar, but vegetarians consume animal products that are not meat, such as dairy products and eggs.

As our page on Ethical Food Consumption makes clear, these choices are absolute. However, plenty of people also make the choice to consume less meat, and follow a more plant-based diet, rather than being vegan.

The Arguments for Veganism

There are three main arguments often made in favour of veganism.

These are:

  1. Veganism means you stop exploiting animals and avoid the use of cruel and inhumane farming practices.

    This makes sense in the immediate term, but actually feels more like an argument to improve farming practices. We have to recognise that farmers are running businesses. If nobody ate meat, they would not produce it. If we want farm animals to be around, we need to improve how they are farmed—and that means expecting to pay higher prices for our meat.

    You cannot have cheap meat and high quality farming practices, because those practices are expensive.

    The answer here is really to eat less meat, but be prepared to pay higher prices when you do.

  2. Veganism is better for the environment

    Our page on Ethical Food Consumption sets out the sustainability argument in favour of veganism and vegetarianism.

    It shows very clearly that producing protein from animal sources is more expensive, and produces more greenhouse gas emissions, than producing protein from vegetables. Soy, rice and beans are all cheaper and less damaging to the environment per gram of protein produced than dairy products, poultry, pork, lamb or beef.

    In other words, plant-based alternatives to both dairy and meat are less environmentally damaging than the original.

    Whichever plant milk you choose, it will be environmentally superior to dairy by a long way.

    Tim Spector, Spoon-Fed: Why Almost Everything We’ve Been Told About Food is Wrong

    That is not to say that these alternatives are perfect in environmental terms. Soy and oat milks require the use of land that may lead to deforestation. The production of almond milk places a strain on water resources. However, they are better than dairy milk.

    Switching to plant-based alternatives for at least some meals is therefore going to be better for the environment, even if you don’t cut out meat and dairy altogether.

    There are a few non-food alternative products that you need to be a bit wary about, however. Top of the list is ‘vegan leather’, also known as fake leather or pleather if it is made from polyurethane. These products are generally NOT plant-based. Instead, they are basically plastic—and we are all aware of the environmental concerns about plastic. These products are probably best avoided altogether.

  3. A vegan diet is better for your health

    The main contention here seems to be that a vegan diet is closer to what our hunter–gatherer ancestors would have eaten. Certainly, many people report feeling better and having more energy on a vegan diet.

    However, there is surprisingly little evidence of the health benefits of a vegan diet.

    There have been several studies on this, and the results are mixed. This is partly because many of them were relatively small, with highly select samples, or only followed up their sample for five years. It is hard to see any effect on long-term health, and certainly on death rates, in just a few years. Those studies that exist, however, have generally found no effect of veganism on the risk of developing several diseases, including cancers and coronary heart disease.

    Looking at the studies that showed effects, it seems more likely that the benefits reported by study participants were from eating a wider variety of fruit and vegetables, with less processed foods, than from a vegan diet per se.

    There is more about why this might happen in our page on What is Fibre?

    It is also possible that participants may also have derived benefits from thinking more about food, and being more conscious of what they were eating. This may have encouraged them to eat more healthily. There may also be an element of the placebo effect: they felt that they were eating better, so felt better.

    There is more about the placebo effect in our pages on Positive Body Image and Positive Thinking.

    The idea that the benefits may be from simply eating a wider variety of fruit and vegetables is supported by a relatively large study with a follow-up of 30 years. The researchers found that a lower risk of coronary heart disease was associated with a higher intake of healthy plant-based foods, such as whole grains, nuts, fruits and vegetables. However, people who ate less healthy plant-based foods, such as sweetened drinks, chips, and refined grains, had a higher risk of heart disease.

    In other words, a healthy diet is one that contains plenty of fresh fruit and vegetables, with whole grains, nuts, and legumes. A small amount of meat or fish is unlikely to harm you, especially if you buy and cook high quality meat. The key seems to be to avoid too many processed and refined foods.

Veganism and Processed Foods

One problem with eating a ‘healthy’ vegan diet is implied by the size of the global market for vegan food. Food manufacturers have jumped on the bandwagon, and now offer a huge volume of processed alternatives to meat and dairy products.

You can find vegan cheese and plant milks, as well as non-meat burgers, sausages, steaks, mince and other products.

Unfortunately, these are considerably more processed than the products that they are imitating.

They are designed literally to imitate meat or dairy products, not simply to replace them in your diet. They have been treated to make their ‘mouth feel’ similar to natural products. This means that they often come under the heading of ‘ultra-processed food’. They also contain large amounts of sugar and saturated fats.

These products are unlikely to be healthier than the products that they are replacing. They are best avoided in favour of smaller quantities of higher quality meat, or less processed legumes.

Deficiencies of a Vegan Diet

Are there any nutrients that vegans are likely to find it hard to eat in sufficient quantities?

Traditional thinking said protein and essential amino acids. However, all the evidence is that vegans can obtain sufficient protein through a reasonably balanced diet with a wide range of plant-based foods.

There is more about protein in our page What is Protein?

The thinking about calcium has also been reversed in recent years. In particular, it now seems that you need much less dietary calcium than was thought for healthy bones.

It is therefore likely that vegans can get enough calcium from vegetables such as broccoli and pak choi, together with nuts, seeds and grains.

There is more about calcium, and other minerals, in our page on Dietary Minerals.

However, there are two nutrients that may be a problem for vegans. The first is iron, and the second is Vitamin B12.

Both of these are very hard to get from grains and other vegetables, but very easy to obtain from animal products, including meat, fish, cheese and eggs. You can, of course, take a supplement to fill the gaps in your diet. However, as our page on Supplements makes clear, this is not always advisable, and in some cases, can be harmful. It is probably better to eat a small amount of animal produce to obtain the nutrients you need than to use supplements.

You can find out more about sources of iron and Vitamin B12 in our pages on Dietary Minerals and Vitamins.

In Summary

There is no doubt that shifting to a more plant-based diet is better for the environment.

There is also an argument for putting pressure on farmers and retailers to improve farming practices, and charge more to compensate.

However, the health benefits of a plant-based diet are less easy to establish.

Any benefits reported from a vegan diet seem to come largely from eating a wider variety of vegetables and whole grains, and less processed food, than from a plant-based diet per se. Eating highly processed and refined foods is not good for you whether they are plant-based or derived from animal products.