Nature is huge symbiosis.
Life represents itself in plants, animals and humans.
Certain lifeforms are originally found only in specific regions, separated by distance.
Every natural lifeform is designed by nature itself to life in a fitting environment.
Some plants grow only where it’s cold, others where it’s warm, absorbing nutrients which are consistent with them.
Animals will eat what is present in their environment, be it plants or animals, or both.
Adaption is hardwired in nature.
Cross-pollinating plants and cross-breeding animals results in hybrid lifeforms, which are unnatural.
Transporting certain foods from far away requires always resources.
Natural liquids are river- / springwater, juices, secretions and blood from natural sources.
Genetics are fundamental for nutrition.
Diet XY may work well for individual XZ, but not necessarly for individual XX.