Vegans, a term coined by its founder Donald Watson, are the people who avoid eating products derived from animal origin. That necessarily means not consuming any meat, fish, eggs, dairy products, honey, gelatine etc.
Following a vegan lifestyle, on the other hand, means avoiding all foods and products made from animals i.e. no animal origin foods and no use of leather, wool, silk, cosmetics etc.
Looking at a more precise definition as stated by the Vegan Society, founding body of veganism.‘’A philosophy and a way of living which excludes all forms of cruelty, exploitations of animals for food, clothing or any other purpose and promoting use and development of animal-free alternatives for the benefit of humans, animals and environment” .
People are drawn to veganism for a multitude of reasons, some of which include health, environmental concerns, societal impacts, spiritual beliefs or compassion for animals to name a few.
History of Veganism
Veganism as a philosophy is believed to be inspired by vegetarianism which became a major movement in England and the US in the 19th century .
However, the first practice of vegetarianism can be traced back to ancient eastern civilizations where followers of Jainism, Buddhism and Hinduism abstained from killings animals and followed a strict vegetarian diet [1,2].
Veganism followed thereafter in the 20th century in Great Britain and was introduced by a British woodworker named Donald Watson in 1944 .
Legend has it that tuberculosis was found in British dairy cows theyear before and Watson used this to his advantage, advocating that Vegan lifestyle was a much healthier option .
The vegan movement has gained momentum in recent years as more and more people are being inspired to change their dietary patterns.
However, it is only a small part of the larger Vegetarian community that has been in existence for quite a while and is segmented as per different dietary patterns.
Different Types of Vegetarians
Vegetarians are classified as per the following categories based on their dietary preferences.
Pesco-Vegetarian or Pescatarian
Vegans follow a very strict diet and abstain from consuming any animal products. Eating only a plant-based diet as a whole is considered to be very healthy and vegan tends to have a lower Body Mass Index than non-vegans and are also less likely to become overweight or obese [14-16].
Vegan-diet is also believed to provide additional protection from chronic diseases like cancer, diabetes-2 and cardiovascular diseases and reduce mortality from all-cause [14-16].
Having said that, eliminating all animal products from the diet might increase the risk of potential nutritional deficiencies if the essential nutrient sources are not replaced by the corresponding plant-based sources .
Hence it is recommended to consume a balanced diet consisting of coloured fruits & vegetables, legumes, nuts, beans and sometimes plant-based supplements.
Potential Nutritional Deficiencies
Red blood cells production, Nerve tissue health, regulate brain functions & DNA synthesis 
Deficiency Consequences: Prevent Anaemia, nervous system damage, major birth defects and improves bone health [3,4].
Dairy products, meat, fish, eggs.
Fortified foods like vegan milk, cereals, vegan spreads, nutritional yeast & vitamin supplements.
Absorbs calcium and promotes bone growth, reduction of inflammation, Increases immunity [5,6].
Deficiency Consequences: Cancer, heart diseases, weight gain, depression, high blood pressure .
Fatty fish and fish liver oil, cheese, egg yolk
Mushrooms, fortified cereals, milk, yogurt & orange juice, supplements & of course sunlight.
Strong bones and teeth, muscle health, hormonal secretion, nerve transmission [7,8].
Deficiency Consequences: Kidney failure, vitamin d deficiency, Osteoporosis [7,8].
Dairy products, certain types of fish.
Green leafy vegetables, nuts, sunflower seeds, dried beans, fortified foods, bread, supplements
Oxygenates blood cells & haemoglobin, maintains immune system & cognitive functions .
Deficiency Consequences: Anaemia, fatigue, reduce stamina, increased irritability, lack of focus [9,10].
Seafood, meat, poultry.
All green veggies, tomatoes, potato, legumes, quinoa, tofu, dark chocolate.
Breakdown of carbs, cell functions, immune system functioning, fighting cold, enhances the action of insulin [11,12].
Deficiency Consequences: Hair loss, poor appetite, problems with a sense of smell & taste, frequent infections .
Beef, pork, lamb, fish.
Low in Nuts, whole grains, legumes, yeast and Supplements.
Repair & Maintenance of tissues, bolsters immune health, transports nutrients, provides energy, enzymes .
Deficiency Consequences: Skin, hair & nail problems, loss of muscle mass, bone fracture risk, greater calorie intake 
Meat, fish, poultry, dairy products
Soya, quinoa, legumes, beans, nuts, seeds, green peas, kale, broccoli.