Why do Buddhists say that they should not 吃荤? What is 荤 (hūn)?

I was wondering why someone can’t just say that they should not eat meat versus not eating 荤 (hūn).
What was the difference between the two terms?

Master Sheng Yen has his answer:

Some surprising clarification I got:

  • 荤 (hūn) actually refers to food cooked with the five xin (辛) plants (onions, garlic, Chinese garlic, leeks and asafetida)
  • thus, 荤 (hūn) can include non-meat dishes.
  • “As for not eating fish and meat, the sutras don’t have strict rules about it, but they have strict rules against the five xin” - Master Sheng Yen
  • What is the main reason for avoiding the five xin? Their strong odour can be displeasing to others and they can have undesirable effects on one’s emotion.

Now i know!