I would not eat meat as a child because I saw my grandparents kill birds and rabbits kept specifically for the table. I fed those same animals daily. However, I was ill for most of my childhood and when I was diagnosed with pernicious anaemia, I was very ill indeed (hospitalised). I was lectured by various doctors, nutritionists etc. for many days (when I began to recover) and asked to eat at least some of the foods I wouldn't touch previously, for the sake of my health. Meat of any kind had to be "hidden" i.e minced, and fish similarly. Eggs I would only eat when whisked and had bread soaked in it (Eggy bread) then fried. I still cannot eat meat or fish when it has bones in it, or when it is still recognisable as the animal it was. I could never kill anything, and would die pretty quickly in any survival situation, I'm sure. I even stop my cats going out because they bring back live animals. I can't bear to see them kill other things and eat them, even though I fully accept that it is natural behaviour. Wild things have to kill something else to survive,. Humans are no longer wild, but I understand that our bodies were meant to consume meat in addition to many other foods. That's why our teeth have the shapes they do, and our digestive systems are the way they are! We can only do our best to ensure that anything we eat has been treated to the highest standards. Some scientists believe that plants suffer when they are harvested! Like all living things, we have to eat to survive.
We must each make our own decisions about the way we live. Yes, animals deserve respect and humane treatment. So so people! We have much that needs to be done to improve the lives of all living creatures (preferably before we lose any more species), and I doubt that we will ever make the world a perfect place. We can only do the very best we can under any and all circumstances.