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The Connection Between Sugar and Your Sleep

A few things to know about your sleep and your sugar consumption.

Deposit Photos
Source: Deposit Photos

We are just a month away from the New Year, and many of you have plans to make some healthy new changes. Whether you plan to start the new year with a new diet, such as paleo, keto, Whole 30, or intermittent fasting, your new-and-improved healthy eating and weight-loss strategy is guaranteed to involve reducing sugar.

I’m hearing from a lot of my patients that their sleep has improved since they started their version of eating clean. One of the most potent, underrated benefits of eating well, especially when paired with exercise? A big boost in sleep. Many patients tell me that since they gave their diets a reboot they’re finding it easier to fall asleep, they wake up less often, and they rise in the morning feeling better rested and more energized. (A lot of today’s popular diets also come with potential hazards for sleep. Read up on the pros and cons of keto, paleo, and intermittent fasting here and here.)

For all its benefits, staying away from sugar isn’t easy. I have a serious sweet tooth, so I understand this struggle. You know it’s the right thing to do, but cookies, chocolate, and ice cream just call out to us, don’t they?

Have you committed to reducing your sugar intake this year? Looking for some fresh motivation to limit the sugar in your diet? Spend a few minutes going over some of the biggest ways sugar can prevent you from getting your best sleep.

Sugar reduces sleep quality

There is evidence that consuming more sugar is linked to more restless, disrupted sleep. A 2016 study included healthy volunteers placed into one of two groups. One was fed a controlled diet that limited added sugars and fats, and emphasized fiber. The second was allowed to eat whatever they wanted, in whatever amounts. Researchers found that the second group consumed significantly more sugar and fat—and their diet had an impact on the quality of their nightly rest. The volunteers who consumed diets with more sugar spent less time in deep, slow-wave sleep. This sleep stage is essential for the body’s physical restoration and healing, as well as for maintaining a healthy metabolism and immune function. The volunteers who ate more sugar also took longer to fall asleep. And they experienced more restless sleep, with more frequent awakenings throughout the night.

Some sugary treats also contain caffeine, which will undermine your sleep, especially if you consume it in the evenings. Ever snacked on some dark chocolate and had a fitful night of sleep follow? That’s a one-two combination of sugar and caffeine interfering with your rest.

Sugar stimulates appetite and cravings

Eating sugar activates the brain’s reward circuitry and a complex web of hormones related to hunger and metabolism. (Sugar is such a powerful trigger that even catching sight of a sugary treat is enough to stimulate the brain’s reward system, studies show.) In response to sugar, the brain releases dopamine—a hormone that delivers powerful feelings of pleasure and satisfaction. The more sugar we consume, the less sensitive our brains become to that dopamine rush. We need to produce more dopamine in order to experience the same feelings of pleasure and satisfaction. And that translates into a need to eat more sugar. (If this all sounds a lot like drug addiction, you’re right: The dopamine-activated reward pathways in the brain that are affected by sugar are the same ones affected by alcohol, drugs, and other potentially addictive behaviors like gambling and sex.)

Eating sugary foods—and the additional body fat that typically comes from a high-sugar diet—reduces the effectiveness of hunger-suppressing and metabolism-regulating hormones, including leptin and insulin.

What does this have to do with sleep? Cravings and an appetite distorted by over-consumption of sugar lead to late-night eating that will disrupt your sleep. And that poor sleep, in turn, makes our sugar cravings even worse: A wealth of studies show that poor quality and insufficient sleep interfere with the normal production and function of appetite-regulating hormones including leptin and ghrelin. Poor sleep also interferes with insulin, the hormone that is a key regulator of blood sugar. A regular sugar habit can set in motion a cycle of disrupted sleep and an overstimulated appetite that is tough to break, and over time leads to weight gain, as well as prediabetes and diabetes.

A low-sugar, high-fiber diet that focuses on whole, unprocessed foods will help keep your gut healthy. It will also help you sleep better. A great night of restful sleep is another reward for saying no thanks to the sugar temptations that come our way.

Sweet Dreams,

Michael J. Breus, Ph.D., DABSM

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