If not hunting/ gathering, and it sounds like you don't support agriculture. Do you have a third option?
Switching to a new dietary paradigm that is adopting "unusual" wild, resistant plants instead of domesticated varieties.
- Fresh fruits (any kind of wild or heritage variety) and Starchy tubers (or any other semi_wild root) as a primary source of energy, fiber and vitamins
- Insects/ophidians/amphibians,/gastropodas/fish/eggs/nuts & seeds as a quickly accessible source of protein,
- Wild shoots/mushrooms/algae/leaves (the so called "wild edibles" ; no need more than an handful and they grow just about everywhere in abandoned fields or by the side of the roads), as a source of fresh minerals.
This would be a mixture between the hunter/gatherer and the agricultural lifestyle.
Not to mention the tremendous health/economical/global benefit of this simple but nutritious diet.
NOTE: If you have got a question, an idea and would like to share it, feel free to contact me and I will be more than happy to connect with you.