JUANA SUMMERS, HOST:
Most of us are now back to standard time after winding back the clock this weekend. NPR's Allison Aubrey reports on one strategy to adjust our internal clocks to the dark days ahead.
ALLISON AUBREY, BYLINE: Our bodies don't keep perfect time on their own. Each day we stray a bit from the 24-hour cycle. That's why exposure to light is so helpful. Light is the cue to reset the master clock in the brain, explains Emily Manoogian, a chronobiologist at the Salk Institute.
EMILY MANOOGIAN: Your body is filled with clocks. Every cell in your body that has DNA has a molecular clock that keeps its own time.
AUBREY: It's a very elaborate system that can influence your health in a profound way. She says the challenge is that our clocks can get out of sync, and it's up to us to choose habits to help keep them in rhythm.
MANOOGIAN: The master clock in your brain coordinates all of those other clocks through a series of different external cues we take in by getting light, by getting food, by getting exercise, by telling your clocks what time of day it is.
AUBREY: That's why the timing of the first bite of food you eat each day is important.
MANOOGIAN: Light is really the biggest stimulus to reset the clocks in your brain, but food is a bigger signal to reset the clocks throughout your body, especially your gut. And so that's one of the reasons why making sure you're eating at the right time relative to light is important.
AUBREY: Eating early in the day is a cue to wake up your digestive organs. But by nighttime, the metabolic system is ready for rest.
MANOOGIAN: When you're sleeping, your body expects a fast, and so it kind of shuts down the part of the system that captures glucose for the blood and stores it away. So if you eat in the middle of the night, then your body can't process that.
AUBREY: And that can set the stage for metabolic disease, including diabetes and obesity. As scientists have learned more about the importance of keeping our biological clocks in sync, society has moved in the opposite direction.
MANOOGIAN: We just kind of completely ignore our circadian rhythms. We have light really late at night. There's advertisements for midnight food menus, all kinds of extremes of working around the clock and being awake and entertaining yourself around the clock.
AUBREY: When Manoogian and her colleagues did a study of people at risk of metabolic disease, those who were able to restrict their eating to a 10-hour window saw a significant drop in blood sugar without being asked to cut calories.
MANOOGIAN: It was exciting to see that just the time-restricted eating was able to reduce their risk for Type 2 diabetes by 60%.
AUBREY: The changes can be as simple as eating dinner earlier and skipping an evening snack, but you've got to stick with it to maintain the benefits. Dr. Phyllis Zee is director of the Center for Sleep and Circadian Medicine at Northwestern University. She says when it comes to exercise, morning is best for some - others, afternoon. But the science shows exercising late at night just before bed can disrupt sleep.
PHYLLIS ZEE: There's a peak time for almost every physiological process - the timing of feeding, the timing that you exercise, the physical activity, all of these help and train the clocks in your body so that they're really in sync.
AUBREY: If you eat dinner and go to bed at the same time most nights, your creature-of-habit ways could pay off.
ZEE: The recent science shows that regularity is very important for the circadian system and for health.
AUBREY: Lowering your risks of chronic disease and boosting your sense of well-being. Allison Aubrey, NPR News.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
