When you're exhausted should you concentrate harder or just trust your gut? - Barking up the wrong tree
Sometimes I think sleep is the answer to every problem.
Sleep is fundamental and most people don't get enough so getting more is like steroids.
It's like someone asks "How can I improve my driving?" and the reply that comes back is "First, open your eyes." Immediate dramatic improvement! :)
"Trust your gut when blood glucose levels are low."
Does that mean you should make decisions before eating, not after?
When you have not eaten rely on unconscious thought. When you have eaten you'll be ready for deliberate active decision-making.