Today, sleep is on the forefront of medical research. While there is much more to learn, it is now widely accepted that there are many important biological processes that occur during healthy sleep.
Proper Brain Function
Brain plasticity theory reveals how sleep contributes to proper brain function. Healthy sleep allows neurons to reorganize.
Emotional Well-being
Healthy sleep is necessary for emotional health. During sleep, specific regions of the brain are actively regulating emotion while supporting healthy brain function and emotional stability.
Cellular Restoration
Every cell in your body is designed to restore itself. This happens during deep, restful sleep.
Energy Conservation
The energy conservation theory reveals how our bodies conserve energy during sleep by enabling our body to reduce our caloric requirements.

Weight Regulation
Sleep affects your weight by controlling hunger hormones. Specific hormones including ghrelin, which increases appetite, and leptin, which increases the feeling of being full after eating, are regulated during sleep.
Proper Insulin Function
Some studies suggest sleep may protect against insulin resistance. By keeping cells healthy they are able to process glucose more efficiently. The brain also requires less glucose while sleeping, which may help the body regulate overall blood glucose.
Immunity
Your body makes cytokines during sleep. Cytokines are special proteins that fight infection and inflammation. Certain antibodies and immune cells are also created during healthy sleep. These molecules help defend against illness by destroying harmful germs.
Heart Health
Interrupted or unhealthy sleep has also been linked to risk factors which impact overall heart health. These include hypertension, overactive sympathetic nervous system activity and elevated levels of the stress hormone cortisol.
Healthy Sleep
Proper Brain Function
When you sleep, your brain’s glymphatic (waste clearance) system clears out waste from the central nervous system. It removes toxic byproducts from your brain, which build up throughout the day. This allows your brain to work well when you wake up.
Research suggests that sleep contributes to memory function by converting short-term memories into long-term memories, as well as by erasing, or forgetting, unneeded information that might otherwise clutter the nervous system.
Sleep affects many aspects of brain function, including:
- Learning
- Memory
- Problem-solving skills
- Creativity
- Decision Making
- Focus
- Concentration
Healthy Sleep
Emotional Well-being
Healthy sleep is necessary for emotional health. During sleep, specific regions of the brain are actively regulating emotion while supporting healthy brain function and emotional stability.
Specific brain activity promoting emotional health:
- Amygdala
- Striatum
- Hippocampus
- Insula
- Medial Frontal Cortex
Healthy Sleep
Cellular Restoration
Every cell in your body is designed to restore itself. This happens during deep, restful sleep.
Sleep enables cells to repair and regrow. Many important processes happen during healthy sleep, including:
- Muscle Repair
- Protein Synthesis
- Tissue Growth
- Hormone Release
Eugene AR, Masiak J. The Neuroprotective Aspects of Sleep. MEDtube Sci. 2015;3(1):35-40.
Healthy Sleep
Energy Conservation
The energy conservation theory reveals how our bodies conserve energy during sleep by enabling our body to reduce our caloric requirements.
Evidence for energy conservation during sleep appears as metabolic rates drop while sleeping. Current research indicates that eight hours of sleep for adults can produce a daily energy savings of 35 percent.
Energy conservation promotes:
- Health + Vitality
- Proper Exercise
- Reduced Inflammation
- Wellness
- Better Brain Function
Schmidt MH, Swang TW, Hamilton IM, Best JA. State-dependent metabolic partitioning and energy conservation: A theoretical framework for understanding the function of sleep. PLoS One. 2017;12(10):e0185746. Published 2017 Oct 10. doi:10.1371/journal.pone.0185746
Healthy Sleep
Weight Regulation
Sleep affects your weight by controlling hunger hormones. Specific hormones including ghrelin, which increases appetite, and leptin, which increases the feeling of being full after eating, are regulated during sleep.
During sleep, ghrelin production decreases because your body reduces the calories required to function while you’re asleep.
Poor sleep elevates the production of ghrelin and suppresses leptin. This imbalance makes you hungrier, which may increase the risk of eating more calories and gaining weight.
Interrupted may be associated with increased risk of:
- Obesity
- Metabolic Syndrome
- Type 2 Diabetes
Acute sleep loss results in tissue-specific alterations in genome-wide DNA methylation state and metabolic fuel utilization in humans
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SCIENCE ADVANCES : EAAR8590
Healthy Sleep
Proper Insulin Function
Some studies suggest sleep may protect against insulin resistance. By keeping cells healthy, they are able to process glucose more efficiently. The brain also requires less glucose while sleeping, which may help the body regulate overall blood glucose.
Insulin is an important hormone that helps your cells convert and use glucose, or sugar, for energy. Insulin resistance causes the cells to fail to respond properly to insulin. Insulin resistance can lead to high blood glucose levels and, eventually, Type 2 diabetes.
Some research suggests healthy sleep can protect against insulin resistance.
Mesarwi O, Polak J, Jun J, Polotsky VY. Sleep disorders and the development of insulin resistance and obesity. Endocrinol Metab Clin North Am. 2013;42(3):617-634. doi:10.1016/j.ecl.2013.05.001
Healthy Sleep
Immunity
Your body makes cytokines during sleep. Cytokines are special proteins that fight infection and inflammation. Certain antibodies and immune cells are also created during healthy sleep. These molecules help defend against illness by destroying harmful germs.
During sleep, your body produces cytokines, which are important proteins that fight infection and inflammation. That’s why sleep is so important when you’re sick or stressed. During these times, the body needs even more immune cells and proteins.
Healthy sleep may promote a strong and healthy immune system enabling your body to fight infections.
Motivala SJ, Irwin MR. Sleep and Immunity: Cytokine Pathways Linking Sleep and Health Outcomes. Current Directions in Psychological Science. 2007;16(1):21-25. doi:10.1111/j.1467-8721.2007.00468.x
Healthy Sleep
Heart Health
Interrupted or unhealthy sleep has also been linked to risk factors which impact overall heart health. These include hypertension, overactive sympathetic nervous system activity and elevated levels of the stress hormone cortisol.
Interrupted or unhealthy sleep is associated with:
- High Blood Pressure
- Increased Sympathetic Nervous System Activity
- Increased Inflammation
- Elevated Cortisol Levels
- Weight Gain
- Insulin Resistance