The Optimal Bedtime for Weight Loss and Overall Health: The Science of Healthy Sleep

Sleep is beneficial—this is a well-known fact. But did you know that your sleep-wake cycle affects the production of hormones responsible for feelings of happiness during the day, satiety, and even beauty? Going to bed against your circadian rhythms can lead to serious disruptions in your body, resulting in fatigue and difficulty concentrating. Family doctor Sofya Sobol breaks it down: what are circadian rhythms, and during which hours is the ‘hormone factory’ most productive?

What Are Circadian Rhythms?

Circadian rhythms are internal clocks that regulate the fluctuations in the intensity of biological processes throughout the day. They are directly linked to the cyclical change between day and night. Special cells in the hypothalamus (a part of the brain) control our circadian rhythm. When it gets dark at night, our eyes send a signal to the hypothalamus that it’s time to rest. The hypothalamus, in turn, signals the pineal gland (also part of the brain) to produce melatonin, which makes you feel sleepy. As you fall asleep, opioid hormones with narcotic effects—endorphins and enkephalins—are released, making the process of falling asleep accompanied by pleasant sensations.

The Energy Dips and Peaks

According to family doctor Sofya Sobol, the most significant drop in energy usually occurs in the middle of the night (around 2:00 to 4:00 AM, when most of us are asleep) and immediately after lunch (approximately from 1:00 to 3:00 PM, when many feel the desire to nap).

If you sleep poorly at night (due to work, a child’s colic, teething, or binge-watching the latest season of your favorite show), you will feel these energy dips and peaks more intensely, which can negatively affect your well-being and mood.

The Importance of a Consistent Sleep Schedule

Our biological clocks work best when we go to bed and wake up at the same time every day (and most importantly, at the right time). Good health, normal body function, and the proper rhythm of hormone production in our bodies heavily depend on the correct and natural cycle of sleep and wakefulness.

As we age, our circadian rhythm changes. It’s essential to listen to your body and pay more attention to its signals, such as feelings of sleepiness and bursts of energy. Additionally, developing good sleep hygiene habits can significantly improve the quality of your sleep, making you feel better overall.

General Recommendations for a Sleep Schedule

While everyone’s sleep-wake cycle may differ, there are some general recommendations to help you establish your sleep schedule. One of the most common and challenging recommendations for adults is to go to bed before 10:30 PM.

The Benefits of Going to Bed Before 10:30 PM

The cyclic fluctuations of hormone levels in the body regulate various processes, such as metabolism intensity, appetite, daily activity, intellectual capabilities, libido, and mood. Each hormone is produced at a specific time and under certain conditions. As mentioned earlier, the pineal gland in the brain produces the sleep hormone melatonin (also known as the beauty and youth hormone) in the evening. The production time is from 10:30 PM to 1:00-1:30 AM, and it’s a very capricious hormone. Melatonin is only produced when we sleep and only in complete darkness. It quickly breaks down when light hits the retina, even through closed eyelids.

The Role of Melatonin

Regulates the duration and phases of sleep.
Regulates mood, feelings of happiness/depression, appetite, and libido.
Reduces stress hormone levels (cortisol, adrenaline).
Enhances fat breakdown.
Restores the body during sleep.
Promotes muscle mass growth.

During the same period, from 11:00 PM to 1:00 AM, the growth hormone is also produced during sleep.

The Role of Growth Hormone

The growth hormone is the most fat-burning hormone. It stimulates cell reproduction (and thus renewal) and muscle mass growth. Additionally, it activates the accumulation of nutrients in the liver.

During sleep, the production of adrenocorticotropic hormone also decreases, which helps relieve daily tension and makes it easier to fall asleep. If you regularly go to bed late and get little sleep, the production of leptin and ghrelin—the hormones responsible for feelings of fullness and hunger—is disrupted. Leptin is produced by fat cells and reduces appetite while increasing the body’s energy expenditure. In a sense, you sleep and lose weight. Ghrelin stimulates hunger and affects many other physiological indicators, such as blood pressure, heart function, and carbohydrate metabolism.

So, simply by going to bed at a specific time, you can gain numerous benefits for your body. For more information on the importance of sleep, you can visit The Sleep Foundation.