According to diktats of natural science, consuming plain Halal or Zabeeha Halal/kosher will/should not have any separate impact on human body/health. Observation says both work the same way.
But the issue is that human life is divided into living and dying. Such division brings fear to man. Out of that fear is all kinds of true or invented comforting religious beliefs in all traditions to compensate the fear. Insisting on Zabeeha Halal/kosher is one of such security to ensure a rosy life after life. What is before death is more important than after death!