The second core principle of brain based learning according to Funderstanding
Learning engages the whole physiology.
Physiology is the processes or functions in an organism (here, humans, obviously) or in any of its parts. So, all functions--breathing, eating, sleeping, heartbeats--affects learning.
This is why when Ty gets hungry, he throws himself down in an tantrum. The poor kids can't think anymore because his body wants food more than it wants to think. The mind and the body are connected. The better shape of the body and its processes, the easier and better the mind can learn.
For teachers, this is something they always knew but could never put a name with--hormones and chemical processes influence learning. The entire body plays a role in learning. More learning takes place when the body learns as well and when the processes are not overriding the brain's attempt to learn.