It's no secret: We are what we eat. And turns out, we might sleep how we eat, too.
A new study from the University of Pennsylvania's Perelman School of Medicine shows an association between what we eat and how we sleep. The research is published in the journal Appetite.
"In general, we know that those who report between [seven to eight] hours of sleep each night are most likely to experience better overall health and well being, so we simply asked the question, 'Are there differences in the diet of those who report shorter sleep, longer sleep, or standard sleep patterns?'" study researcher Michael A. Grandner, Ph.D., of the Center for Sleep and Circadian Neurobiology at the university, said in a statement.
Researchers examined the daily calories and foods consumed -- down to a glass of water -- by people who were part of the 2007-2009 National Health and Nutrition Examination Survey. They also gathered information on the amount of time the study participants slept, putting them into four categories: "very short" sleepers, who slept fewer than five hours a night; "short" sleepers, who slept five to six hours a night; "standard" sleepers, who slept seven to eight hours a night; and "long" sleepers, who slept nine or more hours a night.
And researchers did, in fact, find an association between the number of calories consumed and how long the study participants slept. Those who consumed the most were more likely to be "short" sleepers. Interestingly enough, "normal" sleepers were the next type to consume a lot of calories, followed by "very short" sleepers and then "long" sleepers, researchers found.
The researchers also identified different associations between sleep time and the types of nutrients the participants ate. For example, very short sleepers consumed less tap water, total carbohydrates and a compound found in red and orange foods, compared with the other kinds of sleepers. Meanwhile, the long sleepers consumed less of a compound found in tea and chocolate, as well as the nutrient choline (in eggs and some meats) than other kinds of sleepers, but more alcohol.
Overall, researchers noted that the very short, short and long sleepers consumed a less varietal diet than those who were considered normal sleepers. The question is now whether changing eating habits can actually affect sleep, as the study only showed an association.
"This will be an important area to explore going forward as we know that short sleep duration is associated with weight gain and obesity, diabetes, and cardiovascular disease," Grandner said in the statement. "Likewise, we know that people who sleep too long also experience negative health consequences. If we can pinpoint the ideal mix of nutrients and calories to promote healthy sleep, the healthcare community has the potential to make a major dent in obesity and other cardiometabolic risk factors."
It's important to note that this study only showed an association and doesn't prove that eating certain foods caused a person to have short sleep, or vice versa -- that having short sleep causes a person to eat certain foods or consume certain nutrients. But still, the findings are interesting because recent research has revealed just how big of an interplay sleep and weight have -- particularly in influencing risk for obesity.
For example, a recent commentary published in the Canadian Medical Association Journal showed that "an accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction program to a patient with obesity."
And in another study, conducted also by Grandner and presented at a meeting of the American Academy of Sleep Medicine and Sleep Research Society, researchers showed that not getting enough sleep can actually affect how hard it is to say 'no' to unhealthy foods, HuffPost's Catherine Pearson reported.