Getting by day to day is and always has been a consuming effort for all life forms. Our own history, given the advantages of physical configuration (as opposed to say bottlenose dolphins, ravens, or pigs) and complex communication skills accelerating creativity (as opposed to limiting evolutionary tangents like chimpanzees), has been one of exceptional development in dealing with life's challenges. Major paths we've taken though are proving to be as much a detriment to our species' longevity (among many others), as they are to our immediate betterment.
Whatever divine presence one might believe in, our physical existence on Earth is contingent upon a conducive biosphere, which in turn is dependent upon powerful natural forces and relationships we're just beginning to understand.
Imagine you're visiting the Tortoise Exhibit at the London Zoo.
Kneeling down to observe their lumbering movements, you mull
over what thoughts they're capable of and how they might
communicate. Careful though, or you might be magically whisked
into their world, as this master wordsmith was.
At the chemical level, food is the brain's primary link to its evolution and its ongoing physiology (i.e. how well it functions). It's scientifically established that diet is correlated with (among other physiological aspects) the brain chemicals that influence mood and behavior [e.g. 6,7,8,9,10,11,12,13,14,15]. That is, diet notably influences the thought processes and emotional reactions that ultimately guide us on our path through life. Thus, if our diet is lacking, then at a minimum our brain is not functioning optimally.