The field of neuroendocrinology showing interconnection between the endocrine and nervous systems is growing rapidly. Human nutrition doesn't have the breadth or depth of novel scientific findings contrasted with neuroendocrinology.
So with podcasters like Kikel, they need to produce entertainment. They'll have entertaining guests, which might be some wacky doctor or eccentric type with an esoteric interest. So this guest might have been studying something like rodent research or in vitro research on brown adipose tissue (BAT) where adipokines (which are an endocrine organ) function in thermogenesis and have some CNS functions relying on mitochondrial FAT oxidation and uncoupling PROTEIN I. How does he relate this curious fact to the audience, but to say, eat your protein and fat because they REJUVENATE the CNS? It's entertaining, interesting, and on some myopic level true. Also, myelin sheath formation/maintenance. Dietary fat is incontrovertibly important for endocrine function. CNS "rejuvenation," a bit of a stretch.
For me, I read an actual quote from Kikel where he claimed there were hundreds of growth hormone isoforms naturally produced in humans. There are 2. That's all I need to know, he is a pure entertainer!