If you woke up feeling jet-lagged this morning you are not alone. A quarter of the world reset their clocks last night to “spring forward” and get ready to enjoy long summer nights, all at the expense of one hour of sleep. 

Although an hour change might not seem like a big deal, it can greatly disrupt your circadian rhythm– the internal 24-hour cycle that keeps all of your body’s systems working properly and in alignment with your daily activities. 

Time changes affect your circadian rhythm

At sunrise a master clock in your brain responds to daylight, telling you it’s time to wake up. This master clock regulates other clocks found in every organ of your body, such as your pancreas, liver and heart. These are known as your peripheral clocks, which respond mostly to external factors such as when you eat.

For example, the clock in your pancreas programs itself to produce insulin– a hormone that regulates blood sugar levels– at your usual mealtimes. When you eat at regular times during the day, you’re keeping your pancreas in sync with your master clock and your body’s natural internal rhythms. 

The circadian rhythms are controlled by circadian clocks or biological clock.
Although an hour change might not seem like a big deal, it can greatly disrupt your circadian rhythm– a built-in 24 hour cycle that keeps all of your body’s systems working properly and in alignment with your daily activities.

Unfortunately, manually changing your bedside clock doesn’t automatically change your master or peripheral clocks. If you are used to eating at 8 am but are eating at 7 am due to the time change, there will be a misalignment between when your body receives food and when it’s programmed to release insulin to handle the sugar in that food, for example.  This means that “all of our internal clocks are not matching up with our activities,” says Dr. Karin Johnson, a sleep medicine specialist and an associate professor of neurology at UMass Chan Medical School – Baystate. This impacts your ability to control your blood sugar, digestion, heart rate and sleep, which can lead to symptoms of irritable bowel syndrome or may lead to other problems in the long-run, such as obesity.

Besides misalignment of our body’s internal clocks, the time change also causes sleep deprivation due to losing 1 hour of sleep.  “Those two factors come together and are typically at the worst in that first week or two after that clock change,” she says. Multiple studies have reported an increase in heart attacks, strokes, work accidents, medical mistakes, and fatal car crashes within that first week.

Those most likely to be affected are people that have to get up for work or school by 7 a.m. “While on average people lose about 19 minutes of sleep every day in Daylight Savings Time, people who get up early lose about 36 minutes of sleep,” says Johnson.

Permanent Daylight Savings Time is not a good move

This week, the U.S senate passed a bill to make Daylight Savings Time permanent starting in 2023. Once thought to save energy, recent research has shown that Daylight Savings Time actually increases heating and cooling costs compared to Standard Time, Johnson explains. This is likely because we now use more electricity to keep our phones and computers going. We also use more heating to keep ourselves warm before sunrise during daylight savings, and many of us use air conditioning  during longer summer days.

Besides increasing energy costs, making Daylight Saving Time permanent could have negative impacts on health, at least for some people in the U.S.  For example, in San Diego, California, permanent Daylight Saving Time would mean that sunrise in late December would happen at 7:47 a.m, and in San Francisco, at around 8:20 a.m, which means starting the school or work day in the dark during the winter. No morning sunlight could have negative effects on sleep and attention span, and it could also lead to heart disease and metabolic problems in the future. This could be avoided if we made winter time (Standard Time) permanent. “The best time for our health to prevent things like obesity and diabetes, to make our heart healthier, have less heart attacks and better [sleep] is to be more aligned with the sun time, which is the Standard Time,” says Johnson.

The bill, known as the Sunshine Protection Act, needs the approval of House of Representatives and President Biden’s signature before it can become law. While we wait on a final decision, here are a few ideas on what to do to adjust to the new time:

Tips to adjust to the new time

Eat with the sun- practice time-restricted eating!

Keeping your food intake limited to sunlight hours (or eating with the sun) will help reinforce your natural circadian rhythm, as both sunlight but also food availability set your internal clocks. This is also called time-restricted eating – and it can lower blood pressure and regulate your blood sugar levels. Finish eating your last meal at sunset or by 7 pm if it gets darker earlier where you live. 

Eating with the sun and enjoying sunlight in the morning can reinforce your body’s natural rhythms.

Enjoy the morning sun

This morning, spend 20 minutes outside to infuse your brain with daylight. If it is raining or snowing, enjoy some bright light through your window. Your body stops making melatonin (the sleep hormone) as soon as it detects bright light and realizes that it’s daytime, which tells your brain that it’s time to wake up. Bright light essentially resets the timer on your body’s cyclical (or rather, circadian) production of melatonin. When you get exposed to sunlight or very bright artificial light earlier in the morning, your body starts to produce melatonin earlier in the evening, which helps you fall asleep faster. To fall asleep more easily, go outside and enjoy the sunshine this morning and tomorrow morning! 

Have a consistent sleep schedule

Keep a more consistent sleep-wake schedule as you adjust to the time change. That means going to bed and waking up around the same time every day. Sleeping in might seem like a good fix for poor quality sleep. However, waking up later than normal may cause you to fall asleep later, which can lead you to sleep less and to feel more tired the next day. 

Need extra help? There are more sleep tips in this blog post