We’ve talked about the importance of sleep and how it affects every aspect of our lives. But, the amount (at least 7 hours a night) isn’t the whole story. According to a U.S. study, adults who have a regular bedtime are likely to weigh less, have a lower blood sugar, as well as a lower risk of heart disease and diabetes than those who don’t have a regular bedtime. In fact, in one study, people with irregular sleep had a higher risk of having a heart attack or stroke within 10 years.
Sleep regularity, also called sleep hygiene, is optimal when someone goes to sleep at the same time each night and wakes up at the same time each morning, including weekends. This helps the body’s circadian rhythm to stay on track and regulate other body functions such as appetite and digestion. People with high sleep irregularity tend to go to bed later, to sleep more during the day, and less at night. They had reduced light exposure, higher daytime sleepiness, and were less active.
People with hypertension tended to sleep more hours, and people with obesity tended to stay up later. Sleep irregularity was also tied to greater stress and depression, which are linked to heart disease and obesity risk as well. According to a study at Duke University Medical Center in Durham, North Carolina, of the three types of sleep problems – duration, regularity and timing (as in a morning lark or night owl)- sleep regularity was the most consistently and strongly associated with health,” said one of the authors of the study, Jessica Lunsford-Avery, “That underscores the importance of it.”
So far the findings from this study show an association and not a cause-and-effect relationship between sleep regularity and obesity, heart and metabolic health. It’s thought there’s something about obesity that disrupts sleep regularity. Or, as some research suggests, perhaps poor sleep interferes with the body’s metabolism which can lead to weight gain- creating a vicious cycle. Regardless, a regular bedtime and wake time is key. When we think about sleep and health, we think about duration or quality, but not until recently did people look at the regularity. In particular, people with shift work jobs or late-night social activities may be disrupting their natural circadian cycles. This results in a body-clock misalignment that can lead to irregular sleep and then irregular eating, which in turn encourages them to eat more calories and reduces their sugar metabolism. It’s imperative to keep a regular schedule as much as possible. That may not be possible every now and then, but being aware of the benefits may help to keep those episodes as infrequent as possible. Fundamental mechanisms are at play, so getting not only the best sleep possible but keeping a regular bedtime, may be one of the most important pieces of advice for good sleep hygiene and ultimately, weight loss.
Targeting and identifying patients with sleep irregularity may represent a very real means to preventing cardiac and metabolic disease. Future studies hope to clarify the causal direction of these effects, but for now the data clearly shows getting to bed at the same time every night, along with at least seven hours of sleep, will keep the weight down. A simple and effective addition to your weight loss program that doesn’t impact what or how much you eat.