Tamasic foods are those, which are dangerous to human body and mind.  Non-vegetarian foods form more than ninety percent of Tamasic food.  So, it is very important that you develop the habit of eating vegetarian food only.

Lion or tiger doesn’t have much choice when it comes to their eating habits.  Somebody has to die for the lion or tiger to live.  However, we human beings have choices.  Nobody needs to die for us to live.  We can live on vegetarian food.  And we can even go to the extent of eating only those food, where the trees or plants need not be uprooted and killed while taking fruits or vegetables from those.

Know the fact that we are all connected.  You feel a binding with your siblings because you find a connection with them.  Your siblings and you feel a binding with your parents because you feel a connection; the parent-children connection.  If there is a pet at home, then you feel the connection even with the pet, same as with any other family member.  Thus, members of a family feel that connection, and care for each other; and try to stick together; and live and let live.

When you raise your consciousness from your home level to the world level, you will feel similar connection with all human being, every animal, and other living beings.  And then it would just make no sense in killing anybody.

Human mind is reflection of the person’s thoughts, words, and deeds.  If your karma involves deeds such as killing, your mind can never experience permanent happiness.  So, if your eating habits causes killing, you need to change that habit.  Opposite of Tamasic food is Sathvikh food.  Develop habit of living on Sathvikh food alone.