Speaking from experience, having poor sleep leads to making a lot of questionable decisions, like ordering a random pasta maker on Amazon or responding to your ex-boyfriend’s 2 a.m. text. According to the results of Well+Good’s sleep survey, feeling le tired is something 92 percent of our readers experience more than once a week. There’s even a cute acronym for this feeling: TATT, or Tired All The Time. But according to a new study, eating a diet high in fiber could help improve sleep.
A large new analysis in the American Journal of Clinical Nutrition looked at the food journals of over 50,000 postmenopausal women using data from the Women’s Health Initiative Observational Study to compare eating habits with the odds of experiencing insomnia. The researchers found that people whose diets had lots of high glycemic index foods (read: foods that have a more dramatic impact on blood sugar levels, like refined carbohydrates and sugars) had higher rates of insomnia, compared to people whose diets were rich in fiber.
The researchers speculate that foods high on the glycemic index (like white bread and my personal fave, fries) could trigger insomnia because they typically cause spikes in the body’s blood sugar levels; unstable blood sugar levels in general are associated with poor quality of sleep.
Speaking of foods and sleep, here’s the case for eating a bit of chocolate before bed:
However, it’s important to note that this study is observational and thus doesn’t show causation, says NYC-based registered dietitian Natalie Rizzo, MS, RD. “That means there is no way to prove that the insomnia was caused by higher intake of sugars, refined grains and starch.” It’s unclear if they took other factors into account, she says, like frequency of exercise, stress, smoking, and alcohol use—all of which can also affect sleep.
However, she notes that the hypothesis is sound. “A spike in blood sugar can cause hunger, irritability and headaches, and all of those things can interfere with sleep. And it’s also well known that people who don’t sleep well tend to have less healthy diets and more incidences of obesity,” she says. “It’s difficult to say whether the exact parameters of this study can be extrapolated to the entire population, but having an overall healthy lifestyle with good nutrition can definitely help contribute to good sleep.”
Rizzo says that the researchers are probably suggesting to eat more fruits, vegetables, and whole grains because these carbs also have fiber. Fiber slows the absorption of sugar so that it doesn’t hit your bloodstream all at once (like a crush on a hot bartender). “The best way to do this is eat foods that are high in fiber, like most vegetables, fruits with the skin on, legumes like lentils, beans and whole grains (like oats and brown rice),” she says.
If you are looking for a pre-bedtime nosh, pair a refined carb with crackers with something that has fiber, suggests Rizzo, “like a handful of nuts or an apple.” Jury is still out on if fiber will help me make better decisions, though.