New Study Makes You Rethink How Much Sleep You Need

There's a constant debate in health circles what matters most diet, exercise, or sleep. The obvious answer is that you need all three of them. But the new large-scale study suggests that sleep might be the most important thing of them all. The researchers analyzed sleep and lifestyle data across the US counties from 2019 to 2025. And what they found was quite interesting. Consistently sleeping less than 7 hours was associated with a shorter life expectancy in the majority of states. The message is quite simple. Don't restrict your sleep to less than 7 hours deliberately. But because we like to go into the details, I'm going to provide a lot more context to these findings. And I'll share with you what is the optimal amount of sleep for you. Let's start with the new study. They looked at all counties in all states in the USA and analyzed over 400,000 individuals. What they found was that sleeping less than 7 hours was associated with greater reduction in life expectancy than physical inactivity, social connections, and food insecurity. Only smoking was seen to have a higher risk. In this model, the researchers considered factors such as smoking, physical inactivity, food insecurity, and insurance. On the state level, you can see that for example in Oregon, the counties that have the most amount of people getting sufficient sleep have a higher life expectancy and vice versa. The fewer people get sufficient sleep, the shorter their life expectancy is in the state. So this is a pretty linear relationship in this model. Obviously, this is an observational study still and there are a lot of confounding variables that could explain these results. For example, lower inome counties tend to have more people who have to restrict their sleep to less than 7 hours. Now, the researchers did control for these socioeconomic factors, but it's not possible to do so 100%. However, based on all the other studies out there, sleeping less than 7 hours is consistently associated with a higher risk of mortality, heart disease, and Alzheimer's. This meta analysis of 35 studies saw the lowest mortality risk at 7 hours of sleep, and less than that was associated with higher risk. Sleeping over 8 hours was also associated with higher mortality risk and even more so than 6 hours. That's because people who sleep very long usually have some sort of a medical condition or they're sick. People who sleep less than 7 hours or 6 hours might have to do shift work. They might have some medical condition or something else that shortens their life expectancy. One of those things could be obesity and diabetes. The researchers did an additional analysis and added biological mediators such as obesity and diabetes. You can see from the graph that smoking is still the strongest predictor of shorter life expectancy, but now obesity was a stronger predictor than sleeping less than 7 hours. Physical inactivity was still a weaker predictor than sleep, but diabetes is also a factor that contributes to shorter lifespan. It's a bit less than insufficient sleep and on par with physical inactivity. Now, this is quite interesting because it reveals that a lot of the harmful effects of insufficient sleep might come from obesity and diabetes. It also highlights how bad obesity is for you. It's not as bad as smoking, but it's still pretty damn bad. What supports this idea a little bit more is the fact that Japanese people on average sleep 5.9 hours a night. Yet, they're one of the longest living people in the world. Japanese do take a nap in the afternoon, even at work, but that would still keep them under 7 hours. These are two very distinct groups of people. There's a massive difference in the average Japanese person and the average American. First of all, the average BMI in the USA is 25 to 30, whereas it's 21 to 23 in Japan. 40% of adults in USA are obese whereas it's only four to 5% in Japan. Remember that obesity is a much bigger predictor of shorter life expectancy than insufficient sleep. So this is one of the biggest reasons for these findings in the USA study of why shorter sleep was associated with shorter life expectancy. Americans are much more obese and more diabetic than Japanese people who can get away with shorter sleep. Japanese people might be able to get away with shorter sleep without harming their health for some other unknown reason. maybe some genetic factors, but it is true that the average Japanese person is significantly healthier than the average American or the average European for that matter. Healthy people need less sleep, generally speaking, or at least they're not going to end up sleeping over 8 hours on a regular basis. Sick people tend to sleep more, over 8 hours, and people who chronically sleep very short might also increase the risk of certain chronic conditions, specifically Alzheimer's and dementia. This doesn't mean that if you still feel tired at 7 hours of sleep or less that it's good for you or that you're not harming your health. You shouldn't deliberately restrict your sleep to 6 hours or less than 7 hours. Sometimes you need more sleep, sometimes you need less sleep. But if you feel great on sleeping 6 to 7 hours and you don't have other health conditions like obesity, diabetes, or hypertension, then it appears to be that sleeping 6 to 7 hours might be fine for you as long as your other blood markers and biomarkers are good. I want to take a quick break to let you know about my favorite wellness devices, which are the Bont Chargearge red light therapy devices. You've probably seen many of your favorite longer influencers using these red light therapy devices. But do they actually work? Yes, they do. Red light therapy has been shown to have many benefits on skin anti-aging, hormone optimization, pain management, and even exercise performance. I use my device every day for 15 minutes, especially during the winter months when there's not much sunlight. It increases my energy in the morning and makes my skin glow. Just check out the testimonials on the Bont Chargearge website for the before and after pictures of other people. Most real therapy devices don't have the right wavelengths of light, which might mean you're not getting the claimed benefits. Bone charge uses the exact wavelengths of light used in research and they also have near infrared light that's beneficial to the joints. Head over to boncharge.com and use the code seam sim for a 15% discount. So, let's talk about some of the biomarkers you can look at to see if you are sleeping enough or whether or not you're healthy overall. Waist circumference, sleep deprivation can promote visceral fat gain, which accumulates around the organs. Of course, the most important thing is to not over consume food. But if you're dieting while restricting your sleep, then you're going to lose less weight around the stomach. Muscle loss. Sleep restriction also makes you lose predominantly muscle during dieting instead of fat. To lose the most amount of fat and keep the most amount of muscle, you need to be sleeping at least 7 to eight hours. Blood pressure. Sleep deprivation raises blood pressure and stress hormones. If your blood pressure is elevated, then you might not sleep enough. Same with blood sugar. Sleep deprivation worsens insulin sensitivity and raises blood sugar. Low HRV. Due to the higher stress and reduced recovery, your HRV will plummet. Decline in physical performance. If you aren't seeing the progress you want at the gym or you're actually weaker than you were before, then chances are you're not recovering enough and you need to sleep a bit more. Personally, I sleep around 7 hours flat for most nights. I feel great. I don't need caffeine to wake me up or keep me energized throughout the day. I can go throughout the entire day without caffeine. But I do notice that whenever my exercise volume is higher, I also need more sleep. If I don't exercise, then I can even sleep 4 to 5 hours and be completely fine. So, how much sleep you need depends a lot on how much recovery your body needs and what's your health status. As a general rule of thumb, try to get at least 7 hours, maybe up to 8 hours if you feel like it. But if you feel fine on 6 to 7 hours with all things being considered, that should also be fine. Just monitor your overall health. If you want to know how I got my sleep scores from 75 to 100, then check out this video