As I have seen many guys asking this question many times, I would like to tell you complete details before you decide if you want to be vegetarian or non vegetarian Hinduism or sanatan dharma never brings in any strict code of conduct or restriction on being vegetarian or non vegetarian and even if you get any such reference anywhere in our holy books it is not proposed by Hinduism as whole but you might see some suggestions that might be promoting vegetarian diet . it may be for betterment of ecological balance or society. if we talk about Vedic knowledge, From the very beginning Vedic wisdom suggested that that human existance ,society and consciousness will go through many transition forms and metamorphosis before they can get balanced state of self realization/actualization. Our holy texts like purana's and veda's nowhere have said or suggested the total denial of eating non-vegetarian diet and even drinks like madira(alcohol). if you look around the period of which Mandala-7 of the Rig Veda has referred to regarding the the ‘Dasarjana’ battle, we can make out conclusion that it was around 10,000 B.C +/-120 years when subcontinent ?(India, Pakistan, Bangladesh etc)were cold in that period after the long sting of ice age. It was not practical enough for humans to be complete vegetarians or it was not physible to avoid intoxicating drinks in such cold weather and The concept of vegetarian diet & avoiding all forms of liquor or intoxic drinks emerged in much later time when the climate started to get warmer due to a sudden shift in Earth's rotational axis from 24 degrees to 23.50 degrees around 3,100 BC and when Advaita theory was gradually getting into the society and this is same time span when one of our most respected "Swaraswati River" changed its course and eventually dried up. Now next question that will pop up in your mind is then When did we start to move towards vegetarian diet ? Around 850 BC the Jainism came with concept where ideal form of food was vegetarian. Jainism firmly went against the 'Manu Smriti' idea in chapter 5 verse 30 which says “The eater who eats the flesh of those to be eaten does nothing bad, even if he does it day after day, for God himself created some to be eaten and some to be eater.” Their mantra for vegetarian food promoted that ideal form of food for humans should be vegetarian ‘Mahavira’ (24th Tirthankara) who belonged to ‘Lichchavi’ tribe was first person to take complete vegetarian diet and simultaneously there was ‘Shakyan’ tribe which belonged to Gautam Buddha continued with their non-vegetarian diet even when they immerged as one of the major religions of the world around 400BC. the vegetarian concept became a accepted norm in most north India due to 12 years of devastating famines and draught that came in the latter part of north India during the rule of Chandragupta Maurya around 340 BC and this was time when major part of jain community migrated to south India including the kind under the leadership of “Bhadrabahu . Chandragupta Maurya’ ‘Chandragupta Maurya’ and settled around ‘Sravana-Belagola’.Not many people know that the finest of Tamil poems and literature like ‘Jivaka Chintamani’ by Tirutakkatevar and ‘Kural’ by Thiruvalluvar’ were all composed by Jain monks after this mass migration. The Jains of south India laid the foundation of our modern Tamil Grammar and latter laid the foundation of Telegu literature. Those left out regions of ancient bharata where Jainism couldn’t spread properly continued with their non-vegetarian diet. A live example of such thing can be seen in Bengal where even the Brahmins eat non-vegetarian food. However the ideal form of food should be vegetarian was reinforced by Jainism around . Now last question that come out of mind is Should all Hindus become Vegetarian ? well if you ask me ,the answer is very simple the time have changed and Hinduism is like a bark of tree which changes with time. at present time seeing the climatic condition of the globe and depleting digestion power of humans, i would suggest a strong vegetarian diet but this is not a restriction for anyone who counts himself as Hindu.