Vegetarianism is the practice of a diet that excludes all animal, including poultry, game, fish, shellfish or crustacea, and slaughter by-products There are several variants of the diet, some of which also exclude eggs and/or some products produced from animal labor such as dairy products and honey. Properly planned vegetarian diets have been found to satisfy the nutritional needs for all stages of life
It should be noted that most vegetarians also are aware of avoiding products that may use animal ingredients not included in their labels or which use animal products in their manufacturing i.e. cheeses that use animal rennet, gelatin (from animal skin, bones, and connective tissue), some sugars that are whitened with bone char (e.g. cane sugar, but not beet sugar) and alcohol clarified with gelatin or crushed shellfish and sturgeon. Vegetarians often eat free-range as opposed to battery eggs on moral grounds.
Protein intake in vegetarian and vegan diets is only slightly lower than in meat diets and can meet daily requirements for any person. Proteins are composed of amino acids, the vegetable sources with significant amounts of all eight types of essential amino acids are soy, hempseed, chia seed, amaranth, buckwheat and quinoa. It is not necessary, however, to obtain protein from these sources — the essential amino acids can also be obtained by eating a variety of complementary plant sources