How many of us would like to lose a few pounds, but look for external
ways—outside of our bodies—to lose weight? Perhaps we should be
looking more inward, not only at our personal diet and exercise levels,
but the length and level, or phase, of our sleep.
Recently, I read an article in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. In it, researchers from St. Luke's-Roosevelt Hospital and Columbia University in New York shed some light on the link between our length and phase of sleep, and hunger and weight gain.
The researchers investigated the effects of “sleep architecture” on hunger to determine whether specific stages of sleep—not just the duration of sleep—affect the appetite and food cravings in healthy adults.
What they found is compelling, and cause for further attention: the length of time of sleep, as well as the percentage of overall sleep in different sleep stages, are associated with decreased metabolic rate, increased hunger, and increased intake of calories, specifically from fat and carbohydrates.
For the study, head researcher Ari Shechter and his colleagues studied a random sample of 27 healthy adults between the ages of 30 and 45. The participants underwent two six-day periods of laboratory observation, during which they were slept different lengths of time.
During a "habitual sleep" phase, they were allowed to sleep for nine hours; in the "short sleep" phase, they were allowed just four hours of sleep. Each of the two sleep phase studies were separated by four weeks to make sure the participants fully recuperated, and the women were observed at the same phase of their menstrual cycle. The amount of time spent in each sleep phase—stage 1, stage 2, slow wave sleep (SWS), and REM sleep—was recorded.
For the first four days in both sleep phases, the participants ate meals to meet their energy requirements for weight maintenance. On day four, they rated their hunger and level of desire for different foods. On day five, their resting metabolic rate (RMR) was measured, and for the final two days of the sleep phase studies, the participants were allowed to select their own foods.
The researchers then compared the participants' sleep architectures in both the short sleep and habitual sleep conditions. They also analyzed the relationships between sleep architecture, resting metabolic rate, food intake and food desire ratings.
Shechter and his colleagues found that sleep duration is important, but sleep composition—the time and percentage of overall sleep spent in each stage—also plays an important role in the link between sleep and obesity.
Head researcher Shechter explained, “Any number of various factors like obstructive sleep apnea, certain drugs/medications, chronic exposure to short sleep duration, shift work, jet lag, and changes in the scheduling of the sleep episode, can affect sleep stage quantity and distribution. Our data may provide an explanation for the greater obesity prevalence observed within some of these conditions."
Read the full article, “Changes in Sleep Architecture Increase Hunger, Eating.”
The results of this study remind me of another study I blogged about not long ago on “social jetlag,” another reason for all of us to get more sleep.
Social jetlag is a modern syndrome caused by the discrepancy between our internal body clock and our social clock. And according to Professor Till Roenneberg, Ph.D. at the University of Munich’s Institute of Medical Psychology in Germany, that gap between how much sleep we need and how much we’re actually getting is contributing to our global weight gain and the growing worldwide obesity epidemic.
Each of us has a physiological clock, and that internal clock — also known as our circadian rhythm — is regulated by daylight and darkness to prompt us to go to sleep or wake up. We also have a social clock of things that make up our daily lives, such as our work schedules and social calendars.
The problem is, in our modern society of too-late work hours and too much time in front of computer screens, we are listening to our social clocks more than our physiological clocks, causing a greater sleep gap known as social jetlag. As a person’s circadian rhythm gets more out of whack, their physiological clock gets set later and later, keeping them awake into the night, and feeling chronically tired during the day.
In their study, Professor Roenneberg and his fellow researchers in Munich discovered that people with different weekday and weekend sleep schedules—i.e., those with more social jetlag — were three times more likely to be overweight. That is a significant increase worth repeating: Three times more likely to be overweight!
Furthermore, the body mass index (BMI) of the overweight participants tended to increase as the gap between their weekday and weekend sleep clocks widened.
I applaud the efforts of Roenneberg and his team for their work in particular, because they are bringing a public awareness of a growing syndrome that is affecting many people worldwide — not just shift workers or those with irregular work schedules.
So, why does social jetlag cause weight gain? One of the theories is that late hours encourage irregular meal times and late-night eating, when the body has more difficulty digesting and metabolizing food. That translates into body fat. Another is that chronically tired people are less likely to exercise and more likely to smoke and drink, further contributing to weight gain.
Whatever the causes, it is in all our personal best interests to become more aware of our own physiological clocks and get more restful sleep. Doing so can help us all maintain a healthy body weight, avoid many health problems, feel better and live happier, more productive lives.
So, now that you have this new knowledge about sleep, weight gain, I suggest you give yourself a wonderful personal gift: get more sleep, especially during the holiday season, when many people are overeating and busier than usual. Also spend more time outdoors and exercise. More and better sleep is one of the best gifts you can give yourself for the holidays.
Read Professor Roenneberg and his team’s full report entitled, “Social Jetlag and Obesity,” published in the May 10 issue of Current Biology.
Recently, I read an article in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. In it, researchers from St. Luke's-Roosevelt Hospital and Columbia University in New York shed some light on the link between our length and phase of sleep, and hunger and weight gain.
The researchers investigated the effects of “sleep architecture” on hunger to determine whether specific stages of sleep—not just the duration of sleep—affect the appetite and food cravings in healthy adults.
What they found is compelling, and cause for further attention: the length of time of sleep, as well as the percentage of overall sleep in different sleep stages, are associated with decreased metabolic rate, increased hunger, and increased intake of calories, specifically from fat and carbohydrates.
For the study, head researcher Ari Shechter and his colleagues studied a random sample of 27 healthy adults between the ages of 30 and 45. The participants underwent two six-day periods of laboratory observation, during which they were slept different lengths of time.
During a "habitual sleep" phase, they were allowed to sleep for nine hours; in the "short sleep" phase, they were allowed just four hours of sleep. Each of the two sleep phase studies were separated by four weeks to make sure the participants fully recuperated, and the women were observed at the same phase of their menstrual cycle. The amount of time spent in each sleep phase—stage 1, stage 2, slow wave sleep (SWS), and REM sleep—was recorded.
For the first four days in both sleep phases, the participants ate meals to meet their energy requirements for weight maintenance. On day four, they rated their hunger and level of desire for different foods. On day five, their resting metabolic rate (RMR) was measured, and for the final two days of the sleep phase studies, the participants were allowed to select their own foods.
The researchers then compared the participants' sleep architectures in both the short sleep and habitual sleep conditions. They also analyzed the relationships between sleep architecture, resting metabolic rate, food intake and food desire ratings.
Shechter and his colleagues found that sleep duration is important, but sleep composition—the time and percentage of overall sleep spent in each stage—also plays an important role in the link between sleep and obesity.
Head researcher Shechter explained, “Any number of various factors like obstructive sleep apnea, certain drugs/medications, chronic exposure to short sleep duration, shift work, jet lag, and changes in the scheduling of the sleep episode, can affect sleep stage quantity and distribution. Our data may provide an explanation for the greater obesity prevalence observed within some of these conditions."
Read the full article, “Changes in Sleep Architecture Increase Hunger, Eating.”
The results of this study remind me of another study I blogged about not long ago on “social jetlag,” another reason for all of us to get more sleep.
Social jetlag is a modern syndrome caused by the discrepancy between our internal body clock and our social clock. And according to Professor Till Roenneberg, Ph.D. at the University of Munich’s Institute of Medical Psychology in Germany, that gap between how much sleep we need and how much we’re actually getting is contributing to our global weight gain and the growing worldwide obesity epidemic.
Each of us has a physiological clock, and that internal clock — also known as our circadian rhythm — is regulated by daylight and darkness to prompt us to go to sleep or wake up. We also have a social clock of things that make up our daily lives, such as our work schedules and social calendars.
The problem is, in our modern society of too-late work hours and too much time in front of computer screens, we are listening to our social clocks more than our physiological clocks, causing a greater sleep gap known as social jetlag. As a person’s circadian rhythm gets more out of whack, their physiological clock gets set later and later, keeping them awake into the night, and feeling chronically tired during the day.
In their study, Professor Roenneberg and his fellow researchers in Munich discovered that people with different weekday and weekend sleep schedules—i.e., those with more social jetlag — were three times more likely to be overweight. That is a significant increase worth repeating: Three times more likely to be overweight!
Furthermore, the body mass index (BMI) of the overweight participants tended to increase as the gap between their weekday and weekend sleep clocks widened.
I applaud the efforts of Roenneberg and his team for their work in particular, because they are bringing a public awareness of a growing syndrome that is affecting many people worldwide — not just shift workers or those with irregular work schedules.
So, why does social jetlag cause weight gain? One of the theories is that late hours encourage irregular meal times and late-night eating, when the body has more difficulty digesting and metabolizing food. That translates into body fat. Another is that chronically tired people are less likely to exercise and more likely to smoke and drink, further contributing to weight gain.
Whatever the causes, it is in all our personal best interests to become more aware of our own physiological clocks and get more restful sleep. Doing so can help us all maintain a healthy body weight, avoid many health problems, feel better and live happier, more productive lives.
So, now that you have this new knowledge about sleep, weight gain, I suggest you give yourself a wonderful personal gift: get more sleep, especially during the holiday season, when many people are overeating and busier than usual. Also spend more time outdoors and exercise. More and better sleep is one of the best gifts you can give yourself for the holidays.
Read Professor Roenneberg and his team’s full report entitled, “Social Jetlag and Obesity,” published in the May 10 issue of Current Biology.
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