Enforce a firm late-eating cutoff

Stop eating at least 2–3 hours before your target sleep time.

Why it works

Eating triggers a rise in core body temperature, insulin, and digestive activity — all of which are incompatible with sleep onset. The liver clock is especially disrupted by late eating: food arriving when the liver expects a fast activates daytime metabolic programs at night, reducing overnight hepatic repair and increasing next-day insulin resistance. A hard cutoff gives the gut time to clear and core temperature time to drop.

How to do it

1. Decide your cutoff time (e.g., 8 pm if you sleep at 10:30) and mark it in your calendar or with an alarm.
2. Prepare an herbal tea or sparkling water ritual for after the cutoff to handle habitual evening snacking.
3. If hunger is genuine at the cutoff, add more protein to your last meal rather than pushing the window later.
4. Track sleep quality for two weeks with and without late eating to make the link personally visible.

Evidence

Late eating is associated with worse sleep quality, higher BMI, and impaired glucose tolerance in observational studies; the circadian mechanism — peripheral clock disruption — is well characterized. (observational)

Observational association; some individuals with flexible circadian phenotypes show less sensitivity to late eating. Effect size varies.

Sources

• McHill et al. (2017), Later circadian timing of food intake is associated with increased body fat, American Journal of Clinical Nutrition

Common mistake

Setting a cutoff but treating low-calorie foods (fruit, crackers) as exceptions — any calorie intake triggers metabolic activation and clock disruption regardless of amount.