Vegetarians do not eat meat or fish, but generally eat eggs and dairy products. Vegans do not eat any animal products.
Why do some people decide to follow a vegetarian or vegan diet?
People choose to be vegetarian or vegan for ethical reasons or for health reasons. A vegetarian diet can be very healthy but meat is rich in some nutrients. Vegetarians and vegans have to be careful they are not missing out on these nutrients.
Important nutrients for people who follow a vegetarian or vegan diet to consider
For many people, meat is the richest source of protein in their diet. Protein is needed for the body to build and repair cells. The recommended daily intake of protein is 45 g for women and 55 g for men. For vegetarians, eggs are the most complete source of protein.
However, whilst many plant-based foods contain protein too, they may not contain protein in the correct balance that the body needs. Therefore, vegetarians need to make sure they eat a combination of foods to achieve the right protein balance.
There is some protein in grains, in pulses and in dairy products, and if you eat any two of these, the protein will balance. This doesn't necessarily need to be within a single meal, as was previously thought. Examples of protein-balanced meals include cereal with milk, or baked potato with beans and cheese, or dal with rice or chapatti.
Meat and fish are a source of fat-soluble vitamins A, D, E and K, but there are also vegetarian sources for all of them.
Vitamin A is found in eggs and dairy products. A different form of the vitamin, called beta carotene, is found in dark green leafy vegetables and in coloured fruits and vegetables such as mango, carrots and red peppers. Beta carotene can be converted to vitamin A in the body.
Vitamin D is mainly made in our skin by the action of sunlight. However, it is also found in dairy products, mushrooms and in fortified cereals and margarine.
Vitamin E can be found in vegetable oils and spreads, nuts and seeds, and also in green leafy vegetables.
Vitamin K can be found in green leafy vegetables and in dairy products.
Vitamin B12 is almost entirely found in animal products, although it is present in yeast (including yeast extract such as Marmite®) and seaweed. It is also added to some products such as breakfast cereals and soya milk. Vegans may need to take a supplement to make sure they don't become deficient.
Most of the minerals we need are found in a wide variety of foods and anyone eating a varied diet can obtain enough of them. However, vegetarians need to make sure they take in enough calcium and iron.
Calcium is one of the main components of bones, and people with a diet low in calcium may have weak bones. Most people obtain a lot of the calcium in their diet from dairy products. It is, however, also present in leafy green vegetables, dried figs, almonds, oranges, sesame seeds, seaweed and some types of beans.
If non-dairy calcium is eaten with a source of vitamin D, this will help the body absorb the calcium. Vitamin D can be found in eggs and mushrooms, but is mostly made in the skin by contact with sunshine. Some foods are fortified with calcium, such as breakfast cereals, some soya drinks and tofu. These may already have added vitamin D.
Iron is used in the blood to carry oxygen around the body. People with an iron deficiency become anaemic and may feel tired or breathless. For most people, red meat is the richest dietary source of iron. However, there is iron in many other foods and most vegetarians can easily obtain enough from their food. See separate leaflet called Diets Suitable for People with Anaemia.
People who might need to be more careful about getting enough iron include girls and women who have heavy periods, and pregnant women. People who have recently undergone surgery or those who have blood loss for other reasons may also need extra iron.
Vegetarian sources of iron include pulses such as chickpeas and lentils, sprouted seeds and beans, breakfast cereals and bread. Spinach is famous for containing iron, but it is also found in other green leafy vegetables such as broccoli and kale. There is iron in nuts, especially almonds and cashews, and in dried apricots and raisins.
The body can absorb iron from food more easily if it is eaten with some vitamin C. This can be found in most fresh fruits and vegetables, as well as fruit juice. Some things can reduce the amount of iron the body can absorb. Drinking tea with a meal will prevent the iron being absorbed from the stomach.
Omega-3 fatty acids
Omega-3 fatty acids are thought to reduce the risk of heart disease and to boost brain development. They are commonly found in oily fish. However, vegetarians can obtain omega 3 from flaxseeds and flaxseed oil, rapeseed oil, soya oil and soya-based foods, walnuts and also eggs.
More extreme diets
People who choose to follow a raw vegan diet do not eat cooked food. However, they will eat grains, oils and sprouted seeds as well as fruits, vegetables and juices.
People who choose to follow a fruitarian diet eat only raw ripe fruits, nuts and seeds. This includes eating sprouted seeds and dried fruits. It is possible, but quite difficult, to meet the body's nutritional requirements on a fruitarian diet.
Further help & information
Dr Jan Sambrook
Dr Hayley Willacy