Ways to Control How Your Body Adjusts to Time Changes

We can adopt zeitgebers to reset our circadian rhythms and use other strategies to help our bodies adapt to daylight savings time, jet lag, or shift work.

Daylight savings time effects the body much the same way that jet lag does. Shutterstock

Chances are you’ve used a zeitgeber recently, even if you’ve never heard the word.

Zeitgeber is familiar lingo to sleep researchers. It’s a German word for any cue that can set or reset our circadian rhythms. Sometimes, zeitgeber is translated more literally as a “time giver” or an external timing signal.

Bedtime routines, eating schedules, light exposure, and even medications, coffee, or tea are some examples of zeitgebers. We can manipulate zeitgebers as part of a strategy to prevent our circadian rhythms from getting out of whack.

Circadian Rhythms

The human circadian rhythm is an internal clock that governs our sleep-wake cycle. Zeitgebers are like food or fuel that keep the 24-hour cycle humming along like clockwork. Any change in our cues can throw the rhythm off balance.

Zeitgebers could be useful tools in the coming days when most of us set our clocks back an hour as we “fall back” to standard time. We could use that “bonus” hour to run errands, catch up on email, watch a favorite show, or—if we can—stay in bed and snooze.

Sleep is the supreme zeitgeber. That’s why we’re not as likely to struggle with health challenges in the fall as we are with the “spring forward” time change in March. The spring change comes with an uptick in heart attacks, strokes, and car accidents, due to darker mornings and sleep deprivation.

“A lot of people—not just patients but also their physicians—don’t recognize circadian rhythm problems,” Dr. Sally Ibrahim, sleep specialist and associate professor at Case Western Reserve University School of Medicine, told The Epoch Times. “Daylight savings time gets it on people’s radars that we have these clocks in our bodies, and what we do every day will train our internal rhythm.”

Patients whose circadian rhythms are severely misaligned typically end up seeing a sleep specialist like Ibrahim. Signs that your circadian rhythm isn’t synchronized, she said, include:

• Being hungry at irregular times
• Broken sleep or insomnia
• Restless leg syndrome
• Problems concentrating
• Mood disturbances

Hit ‘Reset’

Ibrahim said there’s more we can do beyond getting a few extra winks anytime we feel “off.” Changing daily routines—particularly light exposure and meal schedules—can help re-establish a healthier biological clock.

“We can retrain our bodies to signal us differently,” she said. “If I could have a boot camp for people with circadian rhythm disorders, I’d do it.”

Adopting military-like habits, she said, has the most rapid, profound effect on circadian rhythm. That, in turn, can influence the release of hormones and correct problems with appetite and digestion. Fortunately, simple strategies can prevent circadian rhythms from getting out of whack. The time change can also be a training ground of sorts for jet lag, insomnia, and other circumstances that alter our biological clocks—often without us realizing it.

Increase Light Exposure

The first habit Ibrahim works on is encouraging patients to spend more time outside, specifically allowing the eyes to receive natural light.

“It’s kind of basic if you think about it, but we’re wired to see sunlight in the morning to entrain our internal clocks,” she said. “We need light, especially to wake up, but also to align our circadian rhythm.” 

“Entrain” is another word in the vernacular of sleep specialists. Essentially, it means that when you vary the rhythm of something, you will gradually synchronize with it. Entraining is an easy—not to mention free—solution for biological problems related to sleep or other rhythms that most of us have experienced at one time or another.

Viewing early morning light and as much light as possible throughout the day can help with small circadian rhythm misalignments, like one-hour time changes. Those who work indoors with no natural light are likely to have “dampened” circadian rhythms, Ibrahim said. Living in a place that doesn’t have bright or longer days can also impact your biological clock.

In that case, artificial light may be used as a supplement. Bright light therapy is often used in circadian rhythm disorders such as delayed sleep phase syndrome, a pattern of sleep outside the norm that makes it hard for someone to follow a regular school or work schedule.

Reschedule Your Meals

Changing meal times may also help straighten out your biological clock, particularly if you happen to eat outside traditional mealtimes, Ibrahim said. However, if you happen to be intermittently fasting and are not experiencing sleep issues, the timing of meals won’t be a factor for you.

“If they’re eating at noon and then again at 6 p.m. and now they’re hungry again at 11 or 12 a.m., you can see that their clock is thinking noon is wakeup time, and 6 p.m. is noon,” Ibrahim said. “We can easily use food to entrain our rhythm.”

The power mealtimes can have over circadian rhythm might even improve the health of shift workers. Josiane Broussard, associate professor in the Department of Health and Exercise Science at Colorado State University, is currently putting this to the test in her lab.

Subjects stay awake at night to simulate night shift work but eat at normal meal times—rather than in alignment with a work schedule. Researchers are monitoring their blood glucose levels, in addition to testing memory, performance, and cognition to see if meal timing could mitigate expected health harms from shift work.

“We have designed a special eating schedule so that even though they’re awake overnight, we keep all their eating in the daytime hours, which makes for a weird schedule,” Broussard told The Epoch Times. “We have a theory that people who work this schedule are impaired partially because they’re eating at night when they shouldn’t be, basically when their biology is not prepared to see food coming in.”

Keeping Zeitgebers Natural

Most people only experience small circadian rhythm shifts from time to time. That makes zeitgebers particularly potent. Even implementing exercise at the same time every day or altering socialization—not scheduling large or lively gatherings late at night—can coax your body’s systems to operate as designed, Ibrahim said.

Caffeine, alcohol, and melatonin supplements are all zeitgebers, too. However, experts warn that these synthetic signals can be habit-forming and even addicting.

From a nutritional standpoint, avoid caffeine—because it’s a stimulant, registered dietitian Lena Bakovic with Top Nutrition Coaching told The Epoch Times. Doing so may be the only strategy needed to adjust circadian rhythm, though it’s often overlooked.

Caffeine blocks the neuromodulator adenosine, which is necessary for healthy sleep, according to Bakovic. A byproduct of cellular metabolism, adenosine builds up in the brain while we are awake and active. That buildup makes us naturally feel sleepy.

“Generally speaking, in a normal circadian rhythm, adenosine levels increase as the day progresses so as bedtime approaches, it induces rest. Other neurotransmitters released by caffeine consumption, norepinephrine and dopamine, can also function to increase wakefulness,” she said.

“Some people are more sensitive to caffeine than others, but for most of us eliminating caffeine at least six hours before bedtime is a good rule of thumb,” she added. “Additionally, consuming a large meal or eating close to bedtime can also negatively impact healthy sleep. I usually recommend eating three to four hours before bed to allow sufficient time for digestion while helping with feeling satisfied and preventing hunger.”

Whether dealing with daylight savings time adjustments, jet lag, or acclimating to a different time zone, Bakovic said staying hydrated and eating in line with the time change can help boost energy levels. A little physical activity or increasing exercise can also help.

Times Changes Are Like Jet Lag

Daylight savings time adjustments are like jet lag. Traveling east and losing time can be more detrimental than going west and gaining an hour.

In the same way, the autumn time change is less harmful to our bodies and brains than daylight savings time in March, when we “spring forward” an hour until November. Most people think that’s because we get a “bonus” hour.

However, that’s just a partial explanation, according to Broussard.

“The fall is less disruptive because the human circadian system is slightly longer on average than 24 hours. It’s a little more in line with our physiology to get the extra hour and sleep a little bit more. Whereas in the spring, it’s associated with more sleep restriction,” she stated.

Traveling through one time zone doesn’t typically have a big impact on our biology. Similarly, daylight savings shifts twice a year aren’t problematic for most healthy people, Broussard said.

The bigger issue, she said, is the cumulative impact on our biology from switching out of standard time.

“When we are in daylight savings time, it is offset from the natural physiology of our body. We have light later at night, and we’re potentially out, active, and eating when our body is more geared to sleep and associated behaviors,” Broussard said.

The amassed effect of shifting in and out of standard time is harder to quantify than the few days around the time change, where associations are more clear, she said.

“For a normal healthy person, you can adapt to a shift that’s that small twice a year. It’s not like going to Australia twice a month,” Broussard said.