Salt and sugar (or corn syrup) confuse the tongue and keep it "addicted".

I have removed both (added) salt & sugar from my cooking for a year now and I am finally at a stage where I can actually taste all the ingredients in the food.

Someone else was making a comment about freshness of tomatoes. There isn't any :) Now add to that 0.5 spoons of salt and 1 spoon of sugar and you taste nothing at all. This way "they" can make you consume the most bland ingredients and you won't even notice it.