Veganism is a philosophy  and lifestyle whose adherents seek to exclude the use of animals for food, clothing, or any other purpose.  Vegans endeavor not to use or consume animal products of any kind.

The most common reasons for becoming a vegan are human health, ethical commitment or moral conviction concerning animal rights or welfare, the environment, and spiritual or religious concerns Of particular concern to many vegans are the practices involved in factory farming and animal testing, and the intensive use of land and other resources for animal farming.

Properly planned vegan diets are healthy and have been found to satisfy nutritional needs, and offer protection against heart disease, cancer, and other diseases Various polls have reported vegans to be between 0.2% and 1.3  of the U.S. population, and between 0.25% and 0.4% of the UK population.

thanks to wiki for above

There are probably even less who stick to a completely raw food diet, they are generally the ones who are really glowing!