Tick, Tock: Your Circadian Clock is Knocking
What first comes to mind when you picture a healthy lifestyle? Many of us tend to focus on what we eat and how active we are. But an oft-neglected part of the picture is not just what we do, but when we do it. Establishing a regular sleeping and eating schedule can improve health in as little as one week. Two experts in sleep and metabolism explain why.
Keeping Time
The answer has to do with the circadian clock: an internal biological 24-hour clock thats present throughout the human body, in every cell. The circadian clock machinery evolved to help your body anticipate whats going to happen, says assistant professor in the Department of Nutrition & Integrative Physiology at the 泫圖弝け of Utah College of 泫圖弝け.
Chaix researches the connection between our internal clock and metabolism, or how we take in and use energy from food. Maintaining good metabolic health reduces the risk of type 2 diabetes, heart disease, and many other serious health conditions.
A well-functioning clock helps our bodies prepare for daily life by tweaking our metabolism based on the time of day, Chaix explains.
At night, for example, the clock preemptively routes energy toward consolidating memories and detoxifying the body, which happen most while we sleep. When we wake up in the morning, the clock revs up our metabolism to prepare to eat and be active. Light exposure during the dayand darkness at nightkeep the clock running in time with the outside world.
When You Eat Matters
This means that the exact same meal can impact your body differently, depending on what time of day you eat. Shortly after waking, the body is prepared to digest food with peak efficiency, thanks to increased responsiveness to the blood sugar-lowering hormone insulin. Even if you have a massive amount of carbohydrates, the way your bodys going to metabolize it is very efficient because it is the right time of day to do it, Chaix says. In other words, a big breakfast wont cause the same spike in blood sugar as the same meal eaten later in the day.
On the other hand, eating late at night can be especially unhealthy. Lots of energy is allocated to the brain and the liver at night, to maintain the body processes that happen during sleep. An unexpected midnight snack forces the body to suddenly reroute energy to the digestive system, striking an uncomfortable compromise between digestion and sleep-related processes.
The Importance of a Sleep Schedule
But lack of sleep can disrupt the clock, which in turn disrupts metabolism, warns assistant professor in the College of 泫圖弝けs Department of 泫圖弝け & Kinesiology. When you dont get enough sleep, youre often also exposed to lots of electronic light late at night, which makes the clock try to reset to match the light cycle. Its like youre inducing jet lag continually, Depner says.
And that jet lag has rapid health consequences. Depners research has found that sleep-deprived people are more likely to eat moreand eat late at night, which can noticeably decrease insulin sensitivity in less than a week. We can take people from healthy to a level of insulin sensitivity that would almost be prediabetic in as short as five days, Depner says. Its really scary.
It takes about a week of sufficient sleep to reverse the metabolic changes, he addssleeping in on weekends isnt enough.
Eating late at night can also affect the internal clock of the digestive system, potentially knocking it out of sync with the light-based clock found in the brain. Ideally, eating breakfast shortly after you wake up keeps your digestive system synchronized with your brain.
However, If the food comes when its not supposed to, then the digestive system is running on a time thats different from the brain, Chaix says. Its like having your brain in Boston and your guts in San Diego. Long-term misalignment can weaken the clock as a whole, making it harder to fall asleep and harder to wake up, Chaix says.
How to Set Your Clock
Getting enough sleep and keeping a consistent schedule are often difficultand sometimes impossible. But small steps can help strengthen the circadian clock and improve health even in tough circumstances.
Even if youre not able to get enough sleep, other strategies can help mitigate some of the health consequences, Depner says. Because bright light sets the brains circadian clock, starting your day with plenty of light exposure can help, Depner says, as can avoiding bright electronic light late in the evening. Hes currently testing ways to in people with chronic poor sleep.
Chaix adds that maintaining a regular schedule can be beneficial, even for people who work or are active at night. Consistency is the key, she says. Whatever rhythm you have, stick to it so that your clock can adapt and predict that cycle, even if its not the cycle thats completely the same as the sun. Part of aims to help figure out the healthiest times to eat for people who work night shifts.
While recalibrating ones schedule may seem like a big task, Chaix adds, even small adjustments can help. It doesnt have to be that tomorrow you wake up and you implement all of these all at once, she says. There are little steps, and all of them are toward a mighty goal of improving health.
