Every hunter gatherer culture was/is different, but I don't think any consume large quantities of grains or seeds- that was mostly only made practical as a major source of calories by the development of agriculture.
Oh, okay. I was thinking of un-domesticated seeds like sumpweed when I said that, but wikipedia ways it was "cultivated," so I was wrong.
Dying or becoming severely physically/mentally ill is very likely going to significantly lower the output of your utility function, so it would probably be a very bad idea to ignore the low-hanging resources which can significantly extend the time for which you are alive and well. I have attempted to search LessWrong for a list of such resources, and haven't been able to find one.
Are there any books, websites, or posts that contain significantly low-hanging fruit in this area? If so, please list them in the comments below.