orexin and sleep

He believes this could explain why we naturally feel sleepy after a
meal and also why it can be difficult to sleep when we are hungry,
since the activity of the neurons would be higher when there is less
glucose in the blood.

“We
think orexin neurons make sure that we are awake and alert when hungry,
in order to ensure optimal food-seeking,” Burdakov says. He adds that
it makes evolutionary sense for animals to turn off their wakefulness
and conserve energy once they have eaten their food, since it could be
risky or wasteful to expend too much energy looking for more food.

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