Emil, VRK:
What do you consider natural probably isnt natural at all. Just look for some ways animal breeding and plant cultivation just in order to save some money.
If you for example think that creatine, carnitine, amino acids or some other supplements are unnatural, you can do some research and find out some of these are naturally produced in your own body, probably making it more natural than what you usually eat. Protein drinks are almost entirely made of milk.
If you train athletics or some other sports, the trainer would actually tell you to take some of these. But its your choice, I suggest you to read some boook about nutritions and then you will decide whether to take these or not. I was initially reluctant too, but since I read taking some of these supplements could help me prevent some of my injuries, I decided to give it a try.