We know a lot less about hunter-gatherers than most people think, and hunter-gatherer tribes fluctuate a lot in terms of their diets/lifestyles, as one would expect with the diversity of the world.
Vegetables tend to be low calorie, so you wouldn't expect tribes to expend a lot of effort getting them. That doesn't really apply to a modern environment where getting enough calories isn't a concern and vegetables can be bought at your local supermarket.
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.