Supplements or not?

If we were to go by what self-made dieticians and other such advisors tell us, then we would never eat cooked food. We would live like the guys before homosapiens did; i.e. keeping it raw and cold. But then again, we have another group of people telling us that eating raw food could cause us more health problems e.g. bacterial infections, the existence of worms, etc. Scary! Speaking of raw food, can you imagine chewing raw beef, just because you want to get all the proteins before they are killed by heat?