As well as "fat and calories", cooked food at least has protein and minerals, so that statement is not 100% true.
If you want to go raw, there are a few extra things to consider.
Yes, many fruits, vegetables and nuts can be eaten raw (though they are more digestible if properly prepared.)
But if you want to eat raw grains, they must be fermented for 2-3 days before eating.
And don't forget about your raw animal foods, which are part of every traditional culture's cuisine. It's vital to get good quality, pasture raised food to start. Meat and fish can be frozen for 2 weeks first, in case of parasites, but eggs and dairy are fine to eat raw as long as they are from a safe source.