what did the Holy Bible says about Vegetarian Diet

While the Jewish people were in imprisonment in Babylon, Nebuchadnezzar, the Babylonian king, recruited the most talented and intelligent young Jewish boys to serve in his palace. They were forced to adopt the customs and religious practices of the Babylonians. The Jewish diet was largely comprised of plant foods because of prohibitions against consumption of unclean meats. So thorough were the attempts to brainwash these young men of their former culture and faith in God, that four boys were given new names by the king and became known as Belteshazzar (Daniel), Shadrach, Meshach and Abednego. The king lured the cooperation of these young men by setting aside daily rations of the “king’s food,” choice meat and wine. But Daniel resisted the king’s food, insisting he would not defile himself, since the meat offered by the king had been sacrificed to idols first. 
The commander in charge of the boys feared they would become pale and less energetic than other boys who consumed the king’s selected foods. “I am afraid of my lord the king, who has appointed your food and your drink; for why should he see your faces looking more haggard than the youths who are your own age? Then you would make me forfeit my head to the king,” said the commander. 
But Daniel responded by saying: “Please test your servants for ten days, and let us be given some vegetables to eat and water to drink. Then you let our appearance be observed in your presence and the appearance of the youths who are eating the king’s choice food; and deal with your servants according to what you see.” So he tested them for ten days. And at the end of the ten days their appearance “seemed better and they were fatter than all the youths who had been eating the king’s choice food.” And so the boys continued to eat vegetables, and exhibited unusual intelligence and the king favored them in his service. [Daniel 1: 1-20] 

This account in the Book of Daniel is authenticated by modern science. Today there is avid enthusiasm for vegetarianism, particularly due to the emphasis upon eating more fruits and vegetables to maintain health. Although iron in plant foods is 10 times less absorbable compared to iron from meat, the incidence of iron deficiency anemia among vegetarians is not significantly greater than that of meat eaters.

Resent studies confirm that those who avoid consumption of iron-rich animal products and solely consume a plant food diet, do not become anemic. The increased vitamin C in the diets of vegetarians increases iron absorption from plant foods.

 A study of 11,000 vegetarians in Britain revealed their mortality rates were one-third lower than meat and dairy consumers.  Another study shows that vegetarians have half the mortality rate from cancer and a 60-percent reduction in cardiovascular disease.