How much sleep is enough for good health? What the research says

Sleep is one of the most important pillars of overall health. Failing to get enough sleep has been linked to an increased risk for many health problems, including type 2 diabetes, high blood pressure, obesity, heart disease and stroke, worse mental health, and more. ¹ 

Additionally, poor sleep can have immediate effects on your metabolism, leading to higher glucose levels. ² In turn, higher glucose can lead to worse sleep, creating a vicious cycle. ³
 
If you struggle to sleep, you may be wondering: How much sleep do adults actually need? Achieving quality sleep will improve your overall health, including managing your glucose and metabolism. Keep reading to learn about how much sleep is enough for good health. 

How much sleep is recommended for adults? 

The consensus by leading sleep experts is that adults need between 7 and 9 hours of sleep a night, and these recommendations don’t change much as you age. ⁴ 

However, sleeping more than 9 hours a night may be helpful for certain individuals such as young adults, people who are recovering from sleep deprivation, and people dealing with sickness. ⁵

Have you noticed that you may feel more “awake” after getting less sleep? This happens sometimes when you’re sleep-deprived. Your brain is working overtime to compensate for the sleep you missed by pumping cortisol (the stress hormone) into your body to keep you more awake. Over time, this can lead to emotion regulation issues, decreased cognition, and increased inflammation. ^{6, 7} Cortisol also increases glucose. ⁸  

Does it matter when I sleep? 

When you sleep also has an impact on the quality of your sleep. Maintaining a regular sleep schedule has been found to help regulate your circadian rhythm, which is your body’s “internal clock” that helps you get sleepy at night and feel more alert and awake during the day. ⁹   

Night owls often experience poor sleep quality. Going to sleep before midnight helps regulate your circadian rhythm, whereas individuals who go to sleep after midnight have been found to have a higher risk of psychological disorders, diabetes, and an overall shorter lifespan. ¹⁰

However, squeezing in extra sleep with daytime naps may benefit your overall health, if you’re intentional about it and they’re short. Research has found that naps lasting between 15-30 minutes are the most beneficial and can help increase alertness without affecting your ability to fall asleep at bedtime. ¹¹ Daytime naps can also help maintain brain health as you age. Habitual naps have been linked to larger total brain volume and better cognitive performance. ^{11, 12}

Naps that are an hour or longer have been studied to have several negative effects on health. That’s because naps lasting longer than an hour cause your body to go into the deepest level of sleep, called slow-wave sleep. Waking from this can cause something called “sleep inertia” and disrupt your alertness and wakefulness once your nap ends. ¹³  

One study found that older adults who regularly napped for an hour or longer were 40% more likely to develop Alzheimer’s than participants who did not nap (or napped for less than an hour each day). ¹⁴ Nappers have also been studied to have an increased risk for high blood pressure and stroke compared to non-nappers. ¹⁵

How sleep impacts your metabolism 

Sleep plays a huge role in your metabolism. ¹⁶ A lack of sleep causes an increase in insulin resistance, which impacts hunger and feelings of fullness. ¹⁷ It’s also been linked to craving junk foods that are high in carbs and sugar ¹⁸ and can make it harder to lose weight.   

Insufficient sleep has also been shown to lead to poorer glucose control the following day ² and poor glucose control can lead to poor sleep. ³ While long-term consequences could mean metabolic issues down the road, like type 2 diabetes, the lack of glucose control will also have short-term implications for things outside of sleep like your memory, focus, and mood. ¹⁹ 

In addition to its impact on metabolism, sleep affects practically every part of your body, including your heart health, circulatory system, immune system, respiratory system, memory, cognitive abilities, and more. ⁹

A final note from Lingo 

Sleep is one of the most important factors for good physical and mental health. Adults should aim to sleep 7 to 9 hours each night for the most health benefits. Catching up on sleep with naps that are 30 minutes or less may benefit health, while naps longer than 1 hour may have negative health effects.  

Using a continuous glucose monitor like Lingo can help you understand your habits and patterns and work towards limiting glucose spikes, which may also improve your sleep.   

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