10/22/2026
When I started practicing neurology, the brain was treated as though it operated independently of the rest of the body.
That idea has not held up. The brain is about 2 percent of your body weight and consumes close to 20 percent of your energy. It also stores almost none of its own fuel, so it depends on steady delivery from everywhere else. When insulin signaling degrades, the organ with the highest demand and the smallest reserve is the one that feels it.
Most people can tell you roughly where they stand metabolically. Very few have asked the same question about the brain.
Here’s a free ten question assessment of how well your daily routine is protecting your brain: https://drperlmutter.com/the-brain-defenders-assessment/