Circadian Rhythm

A consistent bedtime helps establish the body's sleep timing. Natural sunlight in early time windows supports circadian health. Morning sunlight soon after waking may support circadian rhythm, dopamine, serotonin, and metabolism. Full-spectrum or lumen-blocking glasses are presented as more comprehensive than simple blue-light blockers for circadian signaling. The source recommends stopping food at least three hours before sleep, with five hours preferred when possible. The claimed link between late-night eating, glymphatic function, and long-term Alzheimer's risk is presented as plausible but not directly evidenced in the transcript. Cortisol and melatonin operate on opposing schedules: cortisol should be high in the morning and low at night, with melatonin the inverse. Cortisol peaks in the morning, around 07:00–08:00, while melatonin peaks at night, around 00:00–03:00. Going to bed at the same time each night reinforces the body's circadian rhythm. Morning light is described as a strong cue for setting or resetting the circadian clock. Circadian timing is presented as a major regulator of sleep, hunger, blood sugar response, and energy. Circadian rhythm coordinates multiple bod…