the biochemistry of rest
Written by Desmond Olubunmi · Founder of Sunya
Architecting your internal chemistry to support the natural descent into sleep. What you consume — and crucially, when — determines whether the biology of the night works for or against you.
Caffeine physically blocks the sleep-pressure chemical adenosine, the substance that builds the biological drive for sleep across the day. Alcohol, despite inducing drowsiness, actively fragments the restorative architecture of the night — particularly the REM sleep in the second half. And because initiating deep sleep requires a drop in core body temperature, eating a heavy meal too close to bedtime keeps the body burning and prevents the thermal descent necessary for rest.
The 2PM caffeine curfew: Caffeine has a half-life of roughly six hours — meaning half of what you drink at 3PM is still active in your system at 9PM. Establish a firm cutoff of 2PM to ensure the stimulant has cleared before your evening wind-down begins.
The alcohol illusion: Do not use alcohol as a sleep aid. It may hasten unconsciousness but chemically fragments sleep, causes overheating and night sweats, and suppresses the critical REM stages. If you drink, finish at least 3–4 hours before bed — or replace it with chamomile tea.
The 3-hour digestive window: Finish your last meal at least 3 hours before sleep to allow the core body temperature to drop naturally. Avoid heavy, greasy, or spicy food in the evening.
Blood sugar stabilisation: Waking at 3AM with a racing heart is often a blood sugar crash triggering a cortisol spike. Build balanced evening meals with proteins, healthy fats, and complex carbohydrates for a slow, steady energy release through the night. Sleep-supporting nutrients include magnesium (leafy greens, nuts) and tryptophan (oats, tofu, seeds).
The hydration taper: Stay well hydrated through the morning and afternoon, but reduce fluid intake 1–2 hours before bed to prevent disruptive awakenings.
Desmond has written more extensively on sleep in The Sleep Rhythm Reset, an Amazon #1 bestseller in its category.
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