Eating Vegetarian Helps Cultivate Meditative Concentration.

The Buddha said in the Śūraṅgama Sūtra that when sentient beings consume pungent and meat foods, there are various harms, which greatly obstruct cultivation of the Path. Therefore, if one wishes to cultivate meditative concentration (dhyāna) well, one must abstain from pungent and meat foods. "Pungent" refers to foods that produce an unpleasant odor once eaten into the body, such as chives, scallions, garlic, garlic scapes, garlic sprouts, onions, and so on; "meat" refers to the flesh of sentient beings as food. 

When these pungent and meat foods are eaten into the body, they make the mind impure, easily give rise to desire and anger, and also easily attract the approach of ghosts and spirits. Ghosts and spirits are fond of pungent and meat foods; they will lick your lips and sniff the odor. This is unfavorable for cultivation and also makes one prone to encountering calamities. It is also a disguised form of killing, and in the future one will have to repay the debt a thousand- or hundredfold. According to the Buddha's teaching in the Śūraṅgama Sūtra, one should abandon pungent and meat foods as soon as possible and enter the Path quickly.