In order to hack sleep, you have to hack billion-year-old evolutionary mechanisms, ones that predate the origin of animals—even the origin of sleep itself.

I’m talking about back when the most complex form of life on Earth was single-cell bacteria floating in the ocean. Peak nutrients were available at noon, when the sun was highest. The sun would come up, and those ancestral bacteria would float up from the cold depths of the ocean. They would reach the surface and get their first jolt of morning sunlight, which would be a reddish color—because, hey, that’s what sunrise looks like when you’re floating in a primordial ocean. And then they would start getting energy from the sun and begin feasting on whatever was in the water around them.

That whole legacy still lives on inside of you. The daily cycle of light and nutrition is encoded into your cells, and it’s persisted for eons because it’s kept us in sync with our planet. By selectively going without—without food, artificial light, or electronic distractions— you can restore harmony with your ancient internal rhythm.

You’re going to combine the timing of food and sleep to trick your brain into moving your sleep window. Think about the stimuli that affect your body clock. The first is light, including its color, intensity and angle. The second is calories, or rather calories consumed.

If you believe you’ll starve without three meals a day, your sleep window will remain frustratingly out of your control. There aren’t yet any ironclad studies to back up my theory, but I estimate that light controls about 70% of the strength of your circadian rhythm, food about 20%, and room temperature is probably the other 10%.

These are the variables we’re going to work on hacking to reset our circadian rhythm. The formula I’ve come up with boils down to this: