May 24, 2021

 by Mitch Potterf

I know, I know, you’re probably tired of us—and everyone else in your life—preaching the importance of getting enough sleep…

If you’re still resisting because the Netflix series you’re watching is way more interesting and addicting than sleeping, maybe this fact will do it for you: 

Those who go to bed and wake up at the same time each morning are less overweight than those who don’t!

New evidence of this came from a Duke University study this month (https://www.sciencedaily.com/releases/2018/09/180921082947.htm) that examined 2,000 adults’ sleep schedules and patterns. The study concluded adults who have a regular bed time and a regular wake-up time are less obese than those who don’t.

On top of this, those with consistent bed and wake times have lower blood sugar levels and are at a lower risk of developing various heart diseases including hypertension and Type 2 diabetes.

The thought behind the evidence is that a consistent sleep schedule helps your body’s circadian rhythm stay on point, and also helps other processes in your body, such as appetite and digestion, function optimally. 

Further, sleep is important for glucose metabolism, so it makes sense that not getting enough of it results in metabolic and endocrine changes, such as a decrease in glucose tolerance and insulin sensitivity, increased levels of hormones, like cortisol and ghrelin, and decreased levels of leptin (a hormone related to appetite). All of this means more hunger and appetite when you sleep less, which can lead to eating too much the next day and ultimately a greater chance of becoming obese in the long term.

The long and the short of it is: Consistent sleep times = better metabolic health and less unwanted obesity!

Of course, we don’t expect you to put all your faith in one study. So, here are some more peer-reviewed evidence about sleep’s connection to metabolism.

• This 2011 study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2929498/) showed a strong link between sleep duration and sleep quality with obesity. 
• This 2010 study (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951287/) assigned participants the number of hours they were allowed to sleep each night (either 5.5 or 8.5 hours) for 14 nights. They all cut their caloric intake by 680 calories and slept in the lab for the duration of the study. Those who slept 5.5 hours lost 55 percent less body fat and 60 percent less lean body mass than those who were allowed to sleep for 8.5 hours.
• This 2012 study (https://www.ncbi.nlm.nih.gov/pubmed/22402738) looked at 245 women on a six-month weight loss program and discovered the women who slept more than 7 hours a night and reported better quality sleep wound up being 33 percent more likely to reach their weight loss target.

Finally, an analysis of 36 studies that included 635,000 people discovered those who don’t get enough sleep are 50 percent more likely to be obese, while a child who doesn’t get enough sleep is 90 percent more likely to be obese than those who do!

If all this blog has done for you so far is stress you out more because you’re a bad sleeper, check out some other recent pieces we have written about sleep, including a common sleep disorder—Sleep Apnea—and tips to improve your sleep.

• Sleep Apnea Part 1 and Part 2 (Link to June 2018 #4 and June 2018 #5 blogs)
• Cognitive Behavioural Insomnia Therapy (Link to September 2018 #5 blog)