If all the food supplements and junk food on earth mysteriously vanished tomorrow and all that was left to eat was really healthy food, by only eating these foods in the most nutritious combinations could we get enough nutrition to stay healthy for the rest of our lives?
It would be the best only if we got rid of the various pollutions on the planet, replaced the over-used, over-fertilized and nutrient depleted and deficient soils... and last but not least...got rid of the numerous stresses that these things and our jobs, etc...of life create. Oh, one more thing...if everyone developed a healthy spiritual life, relationship stresses would be much less, countries might get along better, no war, etc...
THEN...yes, simple food would be enough for our health!
For those of us who live in cities and don't have space to grow our own food, I'd say the answer is no. So much of the "fresh" produce sold in shops has been sitting around in cold storage for too long and has lost many of its nutrients.
or it was picked so early for shipping that the nutrient value never increased. or it was grown as I stated previous, in nutrient depleted soil, over fertilized soil etc... organic and locally grown foods, low or no processed foods are best, even if you have to pay more or spend more time preparing them. It is worth it..but i know doing it everyday i don't even get done sometimes!