People jump into vegetarian or vegan eating with ideas about “saving the planet”, or it being “better for you”. Unfortunately, many have little understanding of the impacts those choices may have on the environment, on societies, and on health; impacts that are a long way off and can be hard to see. But that is for another article. This particular article is giving the “better for you” rationale some pretty close scrutiny.
Being a healthy vegetarian isn’t easy
Eating a vegetarian (or vegan) diet is supposed to be good for you. Which it is. Vegans and vegetarians who eat a traditional vegetarian diet tend to be less overweight, have lower risk of heart disease, diabetes and cancer, and generally live longer and healthier lives than people who eat a more typical western omnivorous diet.

But eating a traditional vegetarian diet means eating actual vegetables. Plus, nuts and seeds and pulses and whole grains and fruit and seaweeds, and even more vegetables. Being a healthy vegetarian takes work. It takes plenty of cooking, and a lot of chewing. Unfortunately, a large proportion of vegetarians and vegans are junk food veggies, which is a whole different thing and does not have the same kind of health benefits.
Humans spent a couple of million years evolving to get where we are today and a lot of that evolutionary process was driven by what we ate and the nutrients we needed. Our digestive system, our teeth, the acidity in our stomach, the length of our gut, all evolved to support life and health on an omnivorous diet. And the nutritional specifications of that diet can be difficult to replicate on a vegan, or even a vegetarian diet. It is certainly more complicated than simply swapping out meat for highly processed meat substitutes and vegetarian ready meals.
Protein
Protein is made up of molecules called amino acids. There are nine amino acids that must come from our diet and animal products (meat, dairy, fish, eggs) provide all of them. Most plant foods don’t. Too little of any one or more of those nine can lead to protein imbalance and possible deficiency. So, vegetarians and vegans need to know how to combine plant foods to get the right mix – and the right balance – of amino acids.
Some plant-based foods do provide all nine amino acids: tofu; tempeh; textured vegetable protein (all made from soya); Quorn; quinoa; buckwheat; hempseed; and spirulina all do. Different types of lentils, peas and beans can be combined in different things eaten across the day to make sure that all nine amino acids are covered. What any vegetarian or vegan decides to do with all of these different ingredients is up to them. The trouble is, too many don’t do anything with them.
Junk food
A lot of modern vegetarians and vegans default to pre-prepared meat substitute products. These products often trumpet about being “plant based”, with the intention of persuading consumers of their environmental and health credentials. Most are ultra-processed foods, made using industrial processing methods, contain up to 30 different factory produced ingredients, instead of just the one natural ingredient (meat) and are high in fat, salt and sugar.

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Ultra-processed food is toxic. It is strongly implicated in the obesity epidemic and consumption of ultra-processed food has been linked with an increased risk of developing a range of diseases including diabetes, high blood pressure, depression, and some cancers: a lot of the things that a vegan or vegetarian diet is supposed to protect against. A recent study looking at the diet of meat eaters, pesca-vegetarians, vegetarians and vegans found that vegans and vegetarians ate the highest proportion of ultra-processed food.
Vitamins and minerals
Converts to vegetarianism or veganism need some understanding of micronutrients. Animal foods provide us with nutrients that it can be difficult, or even impossible, to get from plant foods. All of them are important, not only for our health and wellbeing, but for the health and wellbeing of any children we may have. There are several vitamins and minerals that evidence shows are concerningly low among vegetarians and vegans.
B vitamins
The B vitamins all work together in energy production, in making red blood cells and DNA, in keeping the brain, heart, and nervous system healthy, and in supporting healthy fertility. If any of the B vitamins are low, none of the others work as well as they should.
Although most B vitamins are found in small quantities in some plant food, B12 is only found in animal foods. A study that reviewed 40 studies of B12 levels in vegetarians and vegans from all over the world, found that up to 80% of vegans and 40% of vegetarians who do not eat fortified foods or take food supplements, are deficient in B12.
Iron
Iron is found in plant foods, but how much there is depends on how much was in the soil the plant was grown in. Meat is a far richer source: you would need to eat 400g of spinach to get the same amount of iron as you would from 100g of red meat. Plus, iron from plants is bound up in fibre and only between 2-10% of it is absorbed.
Iron is used to make the proteins that carry oxygen around the body in our blood. It is also needed in energy production, for our immune systems, and in the cognitive development of unborn babies and children. Iron deficiency anaemia is very common among vegetarians and vegans, particularly if they happen to be women.
Calcium
Most people know that calcium is about healthy teeth and bones, but it does a lot more than that. It regulates muscle contractions and transmits nerve signals, including the muscles and signals that keep the heart beating. It sends signals in and out of cells and is part of the blood clotting mechanism. Low levels of calcium increase the risk of bone fractures and can impact on the growth of children. It can also permanently affect how the heart functions.
Although there is plenty of calcium in plant foods, other chemicals in these foods (oxalate, phytate and fibre) can prevent calcium from being absorbed. 45% of vegetarians and vegans have low levels of calcium, possibly because of poor availability from plant foods.
Zinc
Zinc is part of thousands of enzymes that work in every body system and function. Not getting enough zinc means cells don’t divide properly so the growth and development of children (including unborn children) is affected. Without enough zinc, energy production slows down, skin health deteriorates, muscles get weak, the immune system doesn’t function properly, not enough insulin is produced, and what is produced doesn’t work properly.
Although zinc is widely available in plant foods, it needs good quality protein to be absorbed. But vegetarian and vegan diets are often lacking good quality protein, and zinc is needed for iron absorption, so low levels of zinc makes iron deficiency worse. Vegetarians and vegans are often found to have low levels of zinc.
Iodine
Most people in the UK have iodine intakes that are too low. For vegetarians and vegans this is made worse because there are few effective non-animal sources of iodine. Iodine is a key component of thyroid hormones and in regulating energy production. Low intakes of iodine can lead to an underactive thyroid gland.
It is also essential for the healthy growth and development of the brain and nervous system of unborn children and infants. Many vegan and vegetarian women in the UK have intakes of iodine that are so low that they put any children they may have at risk of a lifetime of impaired development and cognitive ability.

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Eat the rainbow
Some of these nutrients can be found in fortified foods particularly breakfast cereals, the most common fortified foods available in the UK. All of them can be found in food supplements, particularly any that have been specially formulated for vegans and vegetarians. Vegetarianism and veganism can be great, but only if you know what you are doing and plan accordingly.
Eat the rainbow – as wide a range of fruit, vegetables, nuts, seeds, pulses, and whole grains as you can. It may be best to avoid, or at least limit, the stuff that creates huge environmental and societal damage, like avocados, soya products, almond milk, bananas and anything made from cashew nuts.
Steer clear of the junk food meat substitute options – if you are being a vegetarian why would you want to eat sausages or burgers? And cook. Real food. Every day.