When it comes to managing your blood sugar, you already know that nutrition and exercise can make a huge impact on your numbers. But, often, one of the “forgotten strategies” for blood sugar management is sleep, says One Drop coach, Sandra, a registered dietitian/nutritionist (RDN) and certified diabetes care and education specialist (CDCES).
Regardless of whether or not you have diabetes, “blood sugar naturally rises at night in all of us, including healthy adults who regularly get the recommended amount of sleep,” explains Brittany Lubeck, a registered dietitian (RD) based in Colorado. “However, it can remain high throughout the day in those with diabetes or insulin resistance.”
From there, it can become somewhat of a vicious cycle. Though experts don’t fully understand the mechanisms underlying the connection between blood sugar and sleep, a lack of sleep seems to be comparable to experiencing chronic stress in the body in that it leads to higher cortisol levels, which can then spike your blood sugar, explains Sandra.
Once your blood sugar has spiked, that in itself can make it difficult to sleep as well, says Erin Decker, CDCES and registered dietitian (RD). Again, experts aren’t totally sure why, but “practically speaking,” says Decker, “high blood sugar makes you go to the bathroom more frequently, which means more nighttime interruptions.” On the flip side, low blood sugar at night (or nocturnal hypoglycemia) can also keep you awake by causing restlessness, irritable sleep, and sweaty, clammy skin.
Then there’s the fact that poor sleep can disrupt the balance between our appetite hormones, adds Sandra. Lack of sleep stimulates the production of ghrelin, a hunger-inducing hormone, and depresses the production of leptin, a hormone that triggers feelings of fullness.
As a result, explains Decker, “when we’re sleep-deprived, we feel hungrier, and we’re more likely to reach for sugary treats for a quick energy boost.” This can not only perpetuate poor sleep habits, but it can also contribute to elevated blood sugar levels, leading to a cycle that can be hard to break.
So, how do we navigate this link between sleep and blood sugar without falling into those patterns?
That’s where nutrition comes in. While the National Sleep Foundation notes that there’s “a lack of direct evidence about specific foods that are good for sleep,” some foods might be able to make you feel sleepy due to their nutrient profiles, says Lubeck. Tart cherries, for example, contain melatonin, a hormone that’s integral to the sleep-wake cycle. Certain types of fish may also promote better sleep because of their vitamin D and omega-3 fatty acid content, both of which support serotonin regulation, another vital hormone of the sleep-wake cycle. Additionally, foods with tryptophan (an amino acid that helps synthesize serotonin and melatonin), such as nuts, seeds, cheese, and poultry, may help you sleep better.
“Foods containing high magnesium, such as nuts, tofu, beans, and bananas, may improve sleep as well,” adds Lubeck.
The key, of course, is to find the balance between eating patterns that both promote healthy sleep and keep your blood sugar levels stable. Here are some ways to make sure you’re on the right track:
Hydrate Throughout the Day So You Don’t Have to At Night
Proper hydration not only helps you manage your blood sugar, but considering how much water you can lose while you sleep, it also appears to be crucial for a quality night of shut-eye—that is, if you’re drinking it at the right time.
“It’s important to stay hydrated, but earlier in the day,” explains Sandra. She recommends cutting off liquids at least one or two hours before bedtime to avoid frequent, disruptive bathroom trips throughout the night.
In terms of what you’re drinking, plain water is always going to be your best bet. When it comes to caffeinated drinks, make sure you’re mindful of your intake, especially later in the day, says Decker. “Caffeine can also raise blood sugar levels in addition to making it harder to sleep at a restful hour,” adds David Ahn, MD, an endocrinologist, program director, and Kris V. Iyer Endowed Chair in Diabetes Care at the Mary and Dick Allen Diabetes Center.
And, while there’s no harm in the occasional nightcap, it’s worth knowing that alcohol can both raise and lower blood sugar, notes Dr. Ahn. Plus, while you may feel sleepier soon after drinking, he says, “alcohol leads to worse sleep quality over the course of the night.”
Make Your Bedtime Snacking Habits Work for You
First, it’s important to recognize that the timing of when you eat can impact both your blood sugar (especially if you live with diabetes) and your sleep quality. In terms of blood sugar, meal timing may affect your circadian rhythm and, in turn, your metabolism and insulin production. As for your shut-eye, “food digestion can be a major metabolic distraction from good sleep,” says Ford Brewer, MD, MPH, a board-certified preventive and occupational medicine specialist.
At the same time, though, you don’t need to go to bed hungry, says Decker. “Have a bedtime snack of carbs and protein or fat to hold you over if needed—for example, whole-grain toast with peanut butter, cheese and crackers, or fruit and yogurt.”
Much like your liquids, aim to put the bedtime snacks away at least two hours before bedtime to avoid indigestion and high blood sugar episodes, suggests Sandra.
Know That Nutrition Always Matters, No Matter What Time of Day It Is
It’s not just about what you eat in the second half of the day or even right before bed. Your day-to-day nutritional choices can affect your blood sugar—which you likely already know—and your sleep health.
“Diets high in refined carbohydrates can disrupt sleep quality,” explains Decker. Why? It all comes back to blood sugar again. Refined carbs lead to rapid spikes in blood sugar, and as we already know, blood sugar spikes can mean more nighttime trips to the bathroom, as well as a flood of hormones such as cortisol that can make you feel wired instead of tired. So, if refined carbs are a regular staple in your meals, you’re basically putting your body through a constant roller coaster ride of unbalanced hormones and blood sugar levels.
Instead, Decker recommends a Mediterranean diet pattern—a heart-healthy way of eating that involves lots of plant-based foods, whole grains, fruits, nuts, seeds, herbs, and spices—or the DASH diet (a.k.a. Dietary Approaches to Stop Hypertension), which limits foods that are high in sodium, saturated fat, and added sugars. Much like the Mediterranean diet, DASH calls for foods such as fruits, veggies, nuts, seeds, whole grains, lean meats, poultry, and fish. (Check out One Drop coach Sandra’s breakdown of the DASH diet and its benefits for blood pressure.)
This article has been clinically reviewed by Jamillah Hoy-Rosas, MPH, RDN, CDCES, and VP of clinical operations at One Drop.