Veganism /ˈviːɡənɪzəm/ is the practice of abstaining from the use of animal products, particularly in diet, as well as following an associated philosophy that rejects the commodity status of sentient animals. A follower of veganism is known as a vegan.

Distinctions are sometimes made between different categories of veganism. Dietary vegans (or strict vegetarians) refrain from consuming animal products, not only meat but, in contrast to ovo-lacto vegetarians, also eggs, dairy products and other animal-derived substances. The term ethical vegan is often applied to those who not only follow a vegan diet, but extend the vegan philosophy into other areas of their lives, and oppose the use of animals or animal products for any purpose. Another term used is environmental veganism, which refers to the avoidance of animal products on the premise that the harvesting or industrial farming of animals is environmentally damaging and unsustainable.

The term vegan was coined by Donald Watson in 1944 when he co-founded the British Vegan Society – it initially meant “non-dairy vegetarian,” although the membership also opposed the consumption of eggs – and in 1951 the society extended the definition of veganism to mean “the doctrine that man should live without exploiting animals.”It is a small but growing movement. Vegan food is becoming increasingly available in supermarkets and restaurants in many countries, and several top athletes in endurance sports such as the Ironman triathlon and the ultramarathon practise veganism, including raw veganism.

A 2009 review of recent studies indicated that vegan diets tend to be higher in dietary fibre, magnesium, folic acid, vitamin C, vitamin E, iron and phytochemicals, and lower in calories, saturated fat, cholesterol, long-chain omega-3 fatty acids, vitamin D, calcium, zinc and vitamin B12.Well-planned vegan diets appear to offer protection against certain degenerative conditions, including heart disease,and are regarded by the American Dietetic Association, the Australian National Health and Medical Research Council, and Dietitians of Canada as appropriate for all stages of the life-cycle.Because uncontaminated plant foods do not provide vitamin B12 (which is produced by microorganisms such as bacteria),researchers agree that vegans should eat B12-fortified foods or take a supplement.

source: Wikipedia

A gluten-free diet (GF diet) is a diet that excludes foods containing gluten. Gluten is a protein complex found in wheat (including kamut and spelt), barley, rye and triticale. A gluten-free diet is the only medically accepted treatment for celiac disease. Being gluten intolerant can often mean a person may also be wheat intolerant as well as suffer from the related inflammatory skin condition dermatitis herpetiformis, There are a smaller minority of people who suffer from wheat intolerance alone and are tolerant to gluten.

“Despite the health claims for gluten-free eating, there is no published experimental evidence to support such claims for the general population.” A significant demand has developed for gluten-free food in the United States whether it is needed or not.

A gluten-free diet might also exclude oats. Medical practitioners are divided on whether oats are acceptable to celiac disease sufferers or whether they become cross-contaminated in milling facilities by other grains. Oats may also be contaminated when grown in rotation with wheat when wheat seeds from the previous harvest sprout up the next season in the oat field and are harvested along with the oats.

The exact level at which gluten is harmless for people with celiac disease is uncertain. A 2008 systematic review tentatively concluded that consumption of less than 10 mg of gluten per day for celiac disease patients is unlikely to cause histological abnormalities, although it noted that few reliable studies had been conducted.

source: Wikipedia