And Esau said to Jacob, Feed me, I pray thee, with that same red pottage; for I am faint..
Genesis 25:30
"Neuroscientists uncovered an energy-saving mode in vision-system neurons
that works at the cost of being able to see fine-grained details.
---When food has been in short supply for a long time and body weight falls
below a critical threshold, the brain reduces its energy consumption by
changing how it processes information.
When our phones and computers run out of power, their glowing 
screens
go dark and they die a sort of digital death. But switch them to
low-power mode to conserve energy, and they cut expendable operations to
keep basic processes humming along until their batteries can be
recharged.
Our energy-intensive brain needs to keep its lights on too. Brain
cells depend primarily on steady deliveries of the sugar glucose, which
they convert to adenosine triphosphate (ATP) to fuel their information
processing. When we’re a little hungry, our brain usually doesn’t change
its energy consumption much.
“What you’re getting in this low-power mode is more of a low-resolution image of the world,” said Zahid Padamsey, the first author of the new study.
If you’ve ever felt that you can’t focus on a task when you’re hungry —
or that all you can think about is food — the neural evidence backs you
up. Work from a few years ago confirmed that short-term hunger can
change neural processing and bias our attention in ways that may help us
find food faster."
Quanta/AllisonWhitten