Cooking our foods kills all enzymes in our food. Enzymes are the 'life' of any raw fruit or vegetables we eat and can be likened to electricity. Just because we can’t see it, this does not mean that it does not exist or is unnecessary.
Enzyme deficient foods should really be considered to be 'hard-to-digest' foods. And a diet high in such hard-to-digest food will cause us to become more frequently tired and increase the ageing process of our bodies. Enzymes can only withstand temperatures from 47 degrees celcius (wet heat) to 65 celcius (dry heat) so if you really want your food to digest easier don’t cook it – or just eat more uncooked foods than cooked foods. Most of us unknowingly kill the majority of our food's goodness in our kitchens.
We should take note that no carnivore (animal or human) can survive very long eating mainly cooked meat that is devoid of active enzymes. In several experiments giving cats only cooked foods for a long period of time showed these cats got much sicker than those fed non-cooked meat. Their offspring were also often sterile and suffered from thyroid problems (Pottinger's cats experiments)
Cooked protein is perhaps the most 'hard-to-digest' food that we can eat, and when incompletely digested protein enters the human colon it putrefies (or ferments) and ammonia is formed. And this ammonia behaves like chemicals which eventually can cause cancer or promote its growth.
It has been said that the energy our body spends to digest three cooked meals a day is about the same as required for doing eight hours of hard labour! No wonder some of us feel exhausted and lack energy! Our bodies can actually utilise some nutrients from cooked food when that is all a deprived body is fed—but it must waste tremendous digestive energy to do so.