To say till what extent a vegetarian diet is healthy. First of all need to understand what vegetarian diet is and what is mean to be healthy. Among the areas of non-traditional food, vegetarian diet is one of the oldest and most common. Vegetarianism - is an ancient healing nutrition system, which has a deep philosophical meaning, and assuming certain lifestyle. Healthy means - a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity. However, to adhere vegetarian diet have both positive and negative sides. Mainly, vegetarian diet negatively affect oldest people. Firstly, how healthy vegetarian diet is depends only on the scale of vegetarianism. Vegetarians refusing meat and all animals products, are highly at risk of vitamin B-12 deficiency, especially additives are necessary for females during pregnancy and for child of vegans. On the other hand, lacto-ovo-vegetarians have no nutrition risk. They don’t get haem iron from meat, however they compensate it with consumption of non-haem iron from ascorbic acid (Thorogood et al 1994). Generally, refusing to meat, decrease possibility to obtain coronary heart disease, hypertension, obesity and conceivably even some cancers. Secondly, scientific studies have established that people who support vegetarianism are lighter in weight than their meat-eating opponents. The distinction of 1 unit of BMI was found by the EPIC study in the Oxford cohort (Spencer et al 2003). Furthermore, lower BMI decrease rate of type 2 diabetes and gallstones. In opposition, DMI start decrease rapidly over the age 60 in vegetarians and mainly in vegans, which leads to complication to control muscle mass. According to this, old vegans suffer from respiratory disorders which influence high mortality among them. Nonetheless, the positive side of lower BMI shows in younger persons, what helps them in lifestyle move faster…