There are many good reasons to switch to a completely plant-based diet, with concerns over animal welfare and the hefty environmental cost of the meat industry being two of the most common. 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”.
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 vegans who are professional sportsmen show. However, as with any diet it takes some planning to eat healthily as a vegan, and if you are committing to an entirely plant-based diet you do 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.
The Theory
Shunning animal-derived foods altogether means saying goodbye to not just meat, fish, eggs and dairy, but also products including marshmallows (which contain gelatin), Worcestershire sauce (anchovies) and some kinds of apple juice (uh, fish bladders). While some treat veganism as a philosophy for living, others call their diet “plant-based”, which gets the point across while also technically having the flexibility to include meat.
RECOMMENDED: How to Get Started with a Plant-Based Diet
The Evidence
The most compelling reason to go vegan or plant-based is protection against the Big C. In a 2016 meta-review of 96 studies, vegan and vegetarian diets were linked to significantly lowered rates of cancer and heart disease. There’s some evidence that a vegan diet can lead to weight or fat loss, but it tends to be difficult to control for other lifestyle aspects in these studies.
The Good
Done properly – by eating a wide array of plant-based foods including legumes, nuts and seeds – vegan diets are among the most nutrient-dense around, and especially high in dietary fibre, magnesium, potassium, vitamins C and E, folate, carotenoids and most other phytochemicals. Protein can be harder to consume, but it’s entirely possible to get enough if you eat properly. Finally, you might help the planet: vegan food tends to come with a much lower carbon footprint than the typical hamburger, though the effect’s often overstated in the media.
The Bad
If you’re not careful, it’s easy to eat too much over-processed food containing high amounts of soya. Plus, it can be tricky to get enough certain nutrients, especially protein, iron and vitamin B12.
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 Expert Verdict
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.
“A healthy vegan diet requires a lot of planning to be balanced and to get all the nutrients you need,” says McManamon. “For example I am sure we would all agree chips aren’t healthy!”
“If you plan and get accurate advice from a dietitian, plant-based diets can be high in fibre, fruit and vegetables and so therefore linked to reduced risk of some chronic diseases like heart disease and cancer.”
Vegan Diet FAQs
What mistakes do people make when switching to a vegan diet?
“I think the most common mistake people make is not doing enough research, which often leaves them feeling restricted and bored with their new diet,” says Jon Venus, vegan bodybuilder and Vivo Life ambassador. “Some people cut out meat and dairy without substituting these foods with plant-based sources such as legumes, tofu, tempeh [an Indonesian soy-based food] and plant milks. This leaves them with far fewer food options and they think that the vegan diet is boring. If you switch, I highly recommend using it as an opportunity to explore new foods and recipes, and to research all the benefits of this new lifestyle. Focus on abundance instead of restriction.”
What’s the key to getting enough protein on a vegan diet?
“If you eat a wide variety of whole, plant-based foods and get enough calories to fuel your training and activity level, you will get all the protein you need to build muscle,” says Scott Shelter, an NSCA-certified coach, owner of Extreme Performance Training Systems and follower of a plant-based diet. “All plant foods contain some protein, so it does help to stop looking at the foods as protein, carbs and fats. Plant-based foods that are more protein-dense are tempeh, tofu, seitan [a Japanese wheat gluten-based food], beans, legumes, nuts, nut butters and seeds. One cup of quinoa [around 170g] contains around 24g of protein and a cup of beans [around 180g] has up to 30g. And don’t overlook protein in grains like oats, which is 6g per cup [around 80g] cooked.
“I make a smoothie with berries, banana, lots of greens like spinach, kale and dandelion greens, and some flax meal and hemp seeds. If you want to ensure your bases are covered, use a high-quality plant-based protein supplement.”
Which essential vitamins or minerals are most lacking from a vegan diet? And what can you do to ensure you get enough?
“Very few,” says Shelter. “Eating a wide variety of fresh fruit and vegetables, grains, beans, legumes, nuts and seeds will give you the most important micronutrients as well as other healthy phytonutrients and fibre. The main worry is vitamin B12, which is easy and cheap to supplement with. But B12 can be a concern for omnivores too – while it certainly can be a problem for vegans, it is a vitamin that anyone can be deficient in.
“I hear all the time that vegans are at risk for iron deficiency but as with B12, that’s not something exclusive to vegans – there are plenty of omnivores who are at risk as well. It’s been reported that the amino acid lysine may be tough to get for vegans who are restricting calories, so if you are vegan and trying to lose weight by restricting calories I’d recommend a lysine supplement, or at least make sure your protein drink of choice contains it.”
The Major Food Groups
Carbohydrates
- What do they do? Make glucose, which is your body’s primary energy source.
- For omnivores: Pasta, bread, rice, potatoes.
- Some great vegan options: Rice, potatoes, carrots, bananas, oranges.
Proteins
- What do they do? Help you bulk up – the body uses protein to build and repair tissue.
- For omnivores: Meats, poultry, fish, dairy products.
- Some great vegan options: Broccoli, lentils, chickpeas, almonds, sunflower seeds.
Fats
- What do they do? An important source of energy and bulk, they also help the body absorb Vitamins A, D and E.
- For omnivores: Dairy products, red meat, fish, poultry.
- Some great vegan options: Avocado, chia seeds, cashew nuts, coconut oil.
Fibre
- What does it do? Helps you to digest your food.
- For omnivores: Cereals, bread, fruit and vegetables.
- Some great vegan options: Raspberries, cabbage, apples, brown rice.
Minerals
- What do they do? Provide calcium for stronger bones, iron, which is an important element of haemoglobin in the blood, and much more.
- For omnivores: Fruit and vegetables.
- Some great vegan options: Kale, apricots, tofu, hazelnuts, figs.
Vitamins
- What do they do? Good for skin, bones, teeth, keeping your body healthy and boosting your immune system.
- For omnivores: Milk, eggs, butter, fruit and veg.
- Some great vegan options: Asparagus, marmite, tomatoes, green veg.
The Recommended Daily Plate for Omnivores and Vegans

For the omnivore (left)
- Fruit and Veg – 1/3 plate
- Bread, rice, potatoes, pasta – 1/3 plate
- Meat, fish, eggs, beans – 1/6 plate
- Milk and dairy – 1/6 plate
For the vegan (right)
- Fruit and Veg – 1/3 plate
- Grains, rice, potatoes – 1/3 plate
- Lentils, beans – 1/6 plate
- Seeds, nuts – 1/6 plate
Enemies Of The Vegan Diet
Vegan no-nos lurk in the most innocent of products.
Beer
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.
Wine
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.
Margarine
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.