The Vegan Diet: What You Need To Know

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Veganism is very much in vogue, with many people dabbling in it through challenges like Veganuary or Macmillan’s Meat-Free March campaigns for a variety of reasons – animal welfare and the hefty environmental cost of the meat industry being two of the most common. The idea that it is a healthy switch is also a popular belief. It’s true that even if you don’t go completely vegan, eating a plant-based diet most of the time is likely to improve your health by increasing your intake of fruit, vegetables and high-fibre foods like legumes. That’s as long as you don’t take “plant-based” to mean “chips”.

If you are switching to a vegan diet for health reasons, then we feel it’s worth pointing out that you could get the same benefits by simply upping your intake of fruit and vegetables, and other foodstuffs that feature prominently in the vegan diet. This way you’re less liable to develop the deficiencies which can come from poorly-planned vegan diets.

If, on the other hand, you’re adopting a vegan diet for ethical reasons, rest assured it is eminently achievable to eat a nutritionally complete vegan diet, and it’s also possible to be a vegan and a very successful athlete as these three cases demonstrate. However, it’ll probably take more planning than you’re used to if you’re going to eat healthily as a vegan, and you will have to consider how you are going to get some of the nutrients people usually get from animal products.

Below you’ll find expert advice on which nutrients vegans should be especially concerned with getting enough of, like protein, iron and vitamin B12, along with a round-up of six things you might consume that can unwittingly ruin your vegan diet thanks to the animal products unexpectedly lurking within.

Five Potential Health Benefits Of A Vegan Diet

Whether the vegan diet is good or bad for you depends entirely on what you choose to eat. Subsisting entirely on chips, for instance, would qualify as a vegan diet. However, the evidence suggests that vegans don’t tend to subsist entirely on chips. In fact, the diet generally leads to some impressive health benefits.

1. A More Varied And Balanced Diet

“Eliminating meat and animal products will inevitably lead you to rely more heavily on other foods,” says Dr Daniel Fenton, clinical director at the walk-in GP clinic, London Doctors Clinic.

“Substitutes usually take the form of wholegrains, fruits, vegetables, beans, peas, nuts and seeds. Since these foods make up a larger proportion of a vegan diet than a typical Western diet, they can contribute to a higher daily intake of certain beneficial nutrients.

"Studies have consistently reported that well-planned vegan diets tend to be higher in dietary fibre, magnesium, potassium, folate, vitamins A, C and E, and phytochemicals – beneficial plant compounds.”

2. Weight Management

“Vegan diets have a tendency to reduce your calorie intake,” says Fenton. “This makes them effective at promoting weight loss without the need to actively focus on calorie restriction.

“Several observational studies show that vegans tend to be thinner and have a lower body mass index (BMI) than non-vegans. In addition, several randomised controlled studies – the gold standard in scientific research – have reported that vegan diets are more effective for weight loss than the reference diets they were compared with.”

3. Reduced Diabetes Risk

“Going vegan may also have benefits for the prevention of type 2 diabetes,” says Fenton. “Vegans tend to have lower blood sugar levels and up to a 50-78% lower risk of developing type 2 diabetes.”

4. Reduced Risk Of High Blood Pressure And Heart Disease

“Eating fresh fruits, vegetables, legumes and fibre is linked to a lower risk of heart disease,” says Fenton. “All of these are generally eaten in large amounts in well-planned vegan diets. Observational studies comparing vegans with the general population report that vegans may benefit from up to a 75% lower risk of developing high blood pressure and up to a 42% lower risk of dying from heart disease.”

5. Reduced Cancer Risk

“According to the World Health Organization, about one-third of all cancers can be prevented by factors within our control, including diet,” says Fenton. "For instance, studies have shown that regularly eating legumes may reduce your risk of bowel cancer by about 9-18%.

“Research also suggests that eating at least seven portions of fruits and vegetables a day may lower your risk of dying from cancer by up to 15%. Vegans generally eat considerably more legumes, fruit and vegetables than non-vegans.

“This may explain why a recent review of 96 studies found that vegans may benefit from a 15% lower risk of developing or dying from cancer. Also, vegan diets generally contain more soy products, which may offer some protection against breast cancer.”

The Potential Risks Of A Vegan Diet

“Animal products are important sources of protein, non-saturated fats, iron, vitamins and minerals in standard Western diets,” says Fenton. “Vegans are required to find alternative sources of these nutrients and poorly planned vegan diets may provide insufficient amounts of some nutrients.” Here’s a list of the main ones.

Beneficial Omega-3 Fats

“Diets that do not include fish, eggs, or seaweeds generally lack the beneficial omega-3 fats EPA and DHA, which are important for optimal nervous system, cardiovascular, eye and joint health,” says Fenton. “Omega-3s also keep inflammation levels in the body low. Humans are able to convert the plant-based omega-3 fat a-linolenic acid, found in nuts and seeds, into EPA and DHA, albeit with a fairly low efficiency and not in the amounts required to achieve the aforementioned benefits. Compared with non-vegetarians, vegetarians and vegans especially tend to have lower blood concentrations of EPA and DHA. Vegans can obtain DHA and EPA from microalgae oil supplements, as well as from foods fortified with DHA and EPA.”

Vitamin B12

“This nutrient is needed to protect nerves and produce healthy red blood cells,” says Fenton. “Vegans typically have a higher prevalence of vitamin B12 deficiency, which can result in anaemia, fatigue, mood disturbance, memory and concentration difficulty, and abnormal neurological symptoms such as paresthesia – pins and needles. B12-fortified plant foods, such as fortified soy, seaweed, cereals and nutritional yeast can replace lost intake. Vitamin B12 intake can also be augmented through vitamin supplements.”


“This is an important nutrient for absorbing oxygen into the blood and transporting it to the cells in the body,” says Fenton. “There is no greater risk of iron deficiency if you’re a vegan or vegetarian; in fact, most people on plant-based diets actually get more dietary iron. However, most people on plant-based diets usually have lower ferritin levels, which is a marker of how much iron is stored in the body.

“This is because heme iron – found in meat and animal sources of protein – is absorbed in substantially higher quantities by the body than non-heme iron found in plant foods. This means that vegans have to eat substantially more non-heme iron to get the equivalent amount of iron from animal sources. Dried beans and dark leafy greens are rich sources of iron and vitamin C, which improves the absorption of non-heme iron.”


“This mineral is crucial for bone health and skeletal development,” says Fenton. “Vegans are at risk of falling short of the recommended daily intake for calcium. Eating more tofu, tahini, almonds and green, leafy vegetables can help to top up calcium levels.”

Vitamin D

“This vitamin protects against multiple cancers and chronic diseases, and helps to strengthen immunity, bones and teeth,” says Fenton. “Regularly consuming more vitamin D-fortified foods and spending time in the sun can help to supplement the natural production of vitamin D in the skin. In the UK, sun exposure is inadequate during the winter months to ensure sufficient production of vitamin D in the skin.

“According to guidelines issued by Public Health England, everyone over the age of one should have 10 micrograms of vitamin D every day during the winter months. This means that some people may need to consider taking a supplement or ensure a sufficient intake of foods fortified with vitamin D.”


“Deficiency of this mineral can lead to hair loss, poor healing of wounds, immunological problems, skin problems and reproductive hormone imbalance,” says Fenton. “Vegans are often considered to be at risk for zinc deficiency due to the high phytate content of a typical vegan diet. Phytates – a common component of grains, seeds and legumes – bind zinc and decrease its availability for absorption by the body. Nuts and seeds are excellent sources of zinc, some of the best being pumpkin seeds, sunflower seeds, walnuts, cashews, almonds, pecans, chia seeds and hemp seeds.”


“Most people know that the maintenance of healthy muscles requires a sufficient intake of protein,” says Fenton. “However, all of our body’s tissues and organs require protein for general maintenance and for making new cells. Our bodies require different types of protein in different tissues and for different functions. Proteins are made up of building blocks called amino acids. When we eat proteins, they are broken down by our digestive tract into individual amino acids, which are then absorbed into the bloodstream.

“Amino acids are transported to our organs and tissues where they are rebuilt to form the exact protein we need, in the right place. Our bodies are also capable of converting one type of amino acid to another. There are certain amino acids which cannot be produced by the body, aka essential amino acids (EAAs), which can only be found from dietary sources. All animal-based proteins are complete sources of protein because they contain all the EAAs, whereas EAAs are not all present in any single plant-based food.

“Therefore, if you remove meat from your diet you should introduce or increase your intake of a range of vegan foods to make sure all EAAs are covered. Knowledge of which foods to mix together is crucial for maintaining optimal health and functioning. It is also important to stay away from nutrient-poor, fast-food vegan options. Instead, base your diet around nutrient-rich whole plants and fortified foods.”

Eat More Of

If you opt for a vegan diet it’s important to make sure you don’t leave yourself short of vital nutrients that are generally found in animal based products. We asked dietitian Rebecca McManamon of the British Dietetic Association for her advice on which nutrients you need to look out for and where you can get them.

Protein: “Eat protein plant sources like soya, tempeh, Quorn (vegan varieties), nuts, tofu, beans, lentils, peas and sweetcorn regularly, and don’t forget that bread is a source of protein for vegans.”

Selenium: “This can be found in some nuts [especially Brazil nuts] and seeds.”

Iodine: “It’s found in its highest amounts in seaweed, and also in small quantities in potatoes and some fruits.”

Iron: “Iron is present in small amounts in pine nuts and green vegetables. Or you can use an iron pot or ‘iron fish’ when cooking. However, you may still struggle to get enough and I would advise assessment by a dietitian to consider if supplements are also required.”

Vitamin B12: “This is almost impossible to achieve through dietary means and I would recommend B12 supplementation to avoid the potentially harmful side effects of deficiency such as nerve damage.”

The NHS also recommends you keep watch on your calcium and vitamin D intake. Since calcium is commonly found in dairy products, and vitamin D in oily fish, red meat and eggs, it’s possible to not get enough of these vital nutrients when following a vegan diet. The NHS has some helpful suggestions.

Calcium: Go for green vegetables like broccoli, cabbage and okra – although the NHS doesn’t recommend spinach for calcium. Other good options are, pulses, sesame seeds, tahini, and both brown and white bread. Dried fruit is good too, but have it with a main meal to reduce the risk of tooth decay.

Vitamin D: Good old-fashioned sunlight – just watch the UV levels and don’t get burned. Fortified spreads can help, and check for added vitamin D in breakfast cereals and unsweetened soya drinks. If it’s still proving hard, look into a vitamin D supplement. Just make such that the vitamin D doesn’t come from animal products.

As you can probably tell, there’s a lot to consider when switching to a vegan diet and it can get a bit overwhelming. That’s why the Vegan Society released a dietitian-backed app to help you keep track of your diet and develop the healthy habits you’ll need if you want to live a healthy, plant-based life.

This basically works as a food diary that asks you questions at the end of the day. Nothing too intense, just a few prompts to get you to log your diet. You can then compare your answers with previous days to see how you’re doing. You’ll learn about the essential nutrients and understand the role of supplementation. It’s available on both Android and iOS.

Enemies Of The Vegan Diet

Vegan no-nos lurk in the most innocent of products.


Many beers, particularly British stouts, are filtered though isinglass – also known as tropical fish bladder membrane. A notable perpetrator was Guinness, however it changed the brewing process and earlier this year confirmed that the black stuff on draught and in bottles and cans was appropriate for vegans.


The “fining” or clarifying process of wine is a gory read: blood and bone marrow, crustacean shells, fish bladder membranes and protein from boiled animal parts all work to filter certain wines.


The go-to spread when butter’s not an option often contains a milk protein called casein (also used in delicious paint and glue), the milk based by-product whey, and gelatine.

Worcestershire sauce

A favourite livener for baked beans, “Worcester” Sauce contains anchovies, despite having no discernible fishy taste.

Orange juice

Fish can stealthily lurk even in the most innocent of products – Tropicana adds omega 3, derived from fish oil, to its Heart Healthy Orange juice.

White sugar

Some refined sugar is filtered with animal bone char to remove the colour and impurities. This gruesome process is difficult to track making some strict vegans give up sugar altogether.

Nick Harris-Fry
Senior writer

Nick Harris-Fry is a journalist who has been covering health and fitness since 2015. Nick is an avid runner, covering 70-110km a week, which gives him ample opportunity to test a wide range of running shoes and running gear. He is also the chief tester for fitness trackers and running watches, treadmills and exercise bikes, and workout headphones.