NOTHING will benefit human health and increase chances for survival of life on Earth as much as the evolution to a vegetarian diet.

So said Albert Einstein, a veggie himself. He was in good company: Plato, Socrates, Gandhi, Pythagoras and Leonardo Da Vinci were all vegetarians too.

While vegetarianism has a long history, it was not until the 1980s that a meat-free lifestyle became a mainstream choice in the UK.

With high-profile adherents such as Paul and Linda McCartney, and companies like the Body Shop raising awareness of green issues, more and more people chose to shun meat. Previously a practice regarded as the choice of cranks and liberals, vegetarianism has steadily grown. From 1984, when surveys first recorded such figures, vegetarians have gone from 2.1 per cent of the UK population to four per cent in 2001.

The estimate is now around six per cent, although the numbers do go up and down depending on the latest BSE, bluetongue, foot-and-mouth, or bird flu scares.

National Vegetarian Week (NVW), the annual awareness-raising campaign promoting inspirational vegetarian food and the benefits of a meat-free lifestyle, takes place from May 19-25. Celebrated by the Vegetarian Society since 1992, the week is now an established event. The Vegetarian Society, the oldest vegetarian organisation in the world (formed in 1847), was the first organisation worldwide to adopt the term vegetarian'. The society's definition of a vegetarian is: Someone who eats no meat, poultry, fish, shellfish or crustacea and also avoids the by-products of the slaughterhouse such as gelatine, rennet and animal fats.' The majority of vegetarians eat free-range eggs.

The best known reason for going veggie is concern over animal welfare and standards in meat production. Every day, in the UK alone, over two million land animals are slaughtered for their meat. Over 70 per cent of the five million pigs in the UK are reared under very intensive conditions, being closely confined indoors for their entire lives. Most sheep - about 36 million in the UK - are slaughtered as lambs at less than one year of age. While the plight of intensively-reared chickens, brought to light recently by Jamie Oliver and Hugh Fearnley-Whittingstall, is such that the rapid and unnatural growth rate of the birds leads to over 25 per cent suffering from impaired movement.

Recently, environmental vegetarianism, a practice adopted because the production of meat by intensive agriculture is environmentally unsustainable, has taken off. Compared with the 13.5 per cent of global greenhouse gas emissions coming from transport, 18 per cent actually comes from livestock production.

Cattle cause the most environmental damage of any non-human species through over-grazing, soil erosion, desertification and tropical deforestation for ranches (livestock production is responsible for 70 per cent of Amazonian deforestation), in addition to their gaseous emissions and manure products. Indeed, studies on world food security estimate that an affluent diet containing meat requires up to three times as many resources as a vegetarian diet.

With global production of meat rising dramatically from 130 million tonnes in the late 1970s to 230 million tonnes in the year 2000, if nothing is done, the environmental impact of meat production will only increase.

When it comes to human health, eating a well-balanced veggie diet means that you are more likely to achieve the recommended five portions of fruit and veg a day, although it is important that veggies consume good sources of protein and iron.

The former can be found in grains, pulses, seeds, nuts, milk, cheese, eggs and meat alternatives such as tofu: the latter abounds in leafy green vegetables, pulses and wholegrain cereals and flours.

For National Vegetarian Week, The Vegetarian Society is challenging people to sign up to the Veggie Pledge,' which might involve anything from trying a veggie meal, to going veggie for the day, week, month, year, or even for life.

Vegetarian food has, after all, come a long way from the days of plain green salads and nut cutlets. To check out The Vegetarian Society's archive of mouth-watering recipes, for more information, or to make your Veggie Pledge', visit www.vegsoc.org Did you know?

One of the founders of the vegetarian movement in this country was a Reverend William Cowherd.

A Mrs J Brotherton wrote the first cookery book devoted to vegetarian recipes in 1812.

Going veggie is an intelligent choice - veggies have been shown to have higher IQs than non-veggies. A recent study showed that young people who made the decision to go veggie went on to have higher intelligence.

Veggies typically have lower rates of heart disease, diabetes, obesity, certain cancers (colon in particular) and lower blood pressure.

Aphrodisiacs from the vegetable kingdom include chillies, asparagus, celery, fennel, garlic and mustard!