Ketones fuel your brain when your body begins burning fat.
Here’s how that process goes:
• After not eating for multiple hours (at least 8-12), the sugar supplies in our blood and liver are empty (since we’ve used them up for energy and they haven’t been replenished with new food).
• Now, our bodies can and need to burn fat instead.
• By burning fat, we end up with ketones which pass the blood-brain barrier (i.e. they can actually reach our brains) to fuel the brain with the majority of its necessary energy.
In other words, you can thank ketones for saving us from extinction! If we hadn’t had this alternative (and preferred) source of fuel during periods of food scarcity, we would have become quite silly as a species. Sadly, our intellect was (and is) really the only advantage we had over lions and tigers and bears (oh my…).
You can actually increase ketones with my most beloved substance…coffee. Two cups of black coffee while fasting will double your ketone levels and help you feel less hungry during the fast. The cherry on top: ketones also jack up BDNF (brain-derived neurotrophic factor) which is the brain’s ultimate neuroprotective protein.
Another factor to this is that our digestive system gets a rest, which means it doesn’t need nearly as much blood flow. And guess where that extra blood can now be shipped off to? Bingo! The brain. The result? More energy for cognitive tasks (like finding food, or more relatable these days—getting some deep work done).