Melatonin

Melatonin is a hormone produced by the pineal gland that regulates the body's internal clock, or circadian rhythm. Its production begins in the evening as darkness falls and peaks at night between 2-4 AM, after which it decreases in response to morning light. Melatonin doesn't directly make you sleepy; rather, it signals to the body that it's time to prepare for sleep.

For weight management, melatonin and sleep quality are surprisingly important. Just one poorly slept night raises ghrelin (hunger hormone) by 28% and lowers leptin (satiety hormone) by 18%. In practice, this means that when poorly rested, a person eats on average 300-400 kcal more per day - often energy-dense, sugary foods. Chronic sleep deprivation (under 6 hours/night) has been linked in studies to a 55% higher obesity risk.

Melatonin production is disrupted particularly by blue light (phones, computers, LED lights) and irregular sleep schedules. Blue light suppresses melatonin secretion by up to 50% if exposure occurs within 2 hours of bedtime.

Practical tips for supporting melatonin production: maintain a regular sleep schedule even on weekends (maximum 1-hour difference), reduce screen time 1-2 hours before bed or use a blue light filter, keep the bedroom cool (16-19 degrees C) and dark, and expose yourself to bright light immediately in the morning. Age reduces natural melatonin production, which is why sleep quality often deteriorates with aging. Melatonin is directly related to cortisol, serotonin, and leptin concepts.

Last updated: March 30, 2026