As the article linked here states:

http://www.punjabonline.com/servlet/community.discussions?Action=doDisplayTopic&Expand=0&Tier=5&Param=49836&Category=3&New=t

Meat eating is not an issue for Sikhism. Our Sikh warriors grew strong on a balanced diet of meat and vegetables. Some Sikhs (due to their previous Hindu Vaishnav beliefs), stayed vegetarian. The two (meat eaters and vegetarian) mutually acceptable Langaar, which was vegetarian.

Kuttha Meat (which is banned for Sikhs), is meat that is rutually slaughtered. Now that could be halal, meat, but it could equally be meat killed by "Bali" (Hindu Sacrifice. It could be Kosher Meat (meat prepared by Jewish sacrifice). The point here is sacrifice. Sikhs believe that the point of sacrifice is futile, since sacrifice is a form of appeasement to God. God needs no such appeasement from killing an animal. That is the whole point behind this.

Meat eating for Sikhs is about individual conscience. If you don`t feel comfortable eating meat, then don`t. If you do, then carry on. Either way it will not make you anymore spiritually enlightened. The 5 things to watch out for in Sikhism are:

Kaam = Obsession with Sex (Lust),

Krodh = Anger or Stubborness,

Moh = Materialism and obsession with People, Places and Things,

Hankaar = Egotism, Bloated Pride,

Lobh = Greed/Selfishness.