The early bird gets the worm -- and the vegetables, fruits and lean proteins, according to an analysis of data from more than 850,000 Jawbone UP fitness trackers from around the world. (Worms might count as a lean protein, now that we think about it.)
In a report on sleep and nutrition released exclusively to The Huffington Post, Jawbone found that users who went to bed at a consistent time every night -- a time earlier than 11 p.m., that is -- logged fewer calories and ate more nutritious food.
In contrast, "night owls" who go to bed between 11 p.m. and 3 a.m. tend to consume more caffeine, alcohol, refined sugars, processed carbs, processed meats and saturated fats than their "early bird" counterparts.
This could have major implications for sleep and weight loss.
"If you go to bed an hour earlier, and do so consistently for a year, in theory, this could add up to [a loss of] 4-5 pounds with no changes in activity," Dr. Kirstin Aschbacher, a data scientist at Jawbone, told HuffPost.
(It's worth noting that Jawbone's definition of a "night owl" is only based on what time you to go bed, not how much sleep you actually get. In other words, the category includes people with shifted sleep schedules and people who simply go to bed late and wake up at a normal hour.)
Jawbone's report dovetails with the existing scientific literature on bedtime and wellness. The relationship between getting more sleep and making better food choices is well-documented. A study published last year in The American Journal of Clinical Nutrition found that people who sleep more tend to eat less saturated fat than their peers who don't get as much rest. And a 2015 study from the University of California, Berkeley, found that teens who go to bed late are more likely to gain weight over a five-year period.
"Night owl" types may wonder what the takeaway is for them. As a group, they tend to eat less nutritious food and more calories overall than early risers.
But the news is not all bad, says Aschbacher, who's a member of the "night owl" camp herself. Even if you're one of those people who goes to bed late and wakes up late, thereby getting a standard amount of sleep, you can still benefit from going to bed earlier than you currently do. And if late sleepers want to lose a few pounds, Aschbacher says, they can focus on the period before their (late) bedtime, when they are most susceptible to snacking.
Jawbone's report draws on self-reported food logs from third-party apps like MyFitnessPal (which raises the caveats that self-reported data is not always reliable, and that people who log their food intake might already be more attentive to their diets than the average person). The company's goal in collecting data and identifying trends is to inspire behavioral change that can lead to better sleep and healthier eating.
Dr. Mitesh Patel, an assistant professor at the University of Pennsylvania's Perelman School of Medicine, said that fitness trackers can be powerful tools of behavioral change, but "the challenge becomes how to design an intervention based on their insights."
"A pop-up notification in the app is a good start," Patel told HuffPost, "but then they have to evaluate the impact of that too."
To that end, Jawbone's data analysis feeds back almost in real time to a "coaching" feature within the app, which makes suggestions based on healthy behaviors that have seemed to work well for other users. Aschbacher said the insights on sleep and nutrition, for instance, have been translated into a recommendation to keep a more consistent bedtime. The next step for her at Jawbone will be to evaluate those interventions.
Patel also said it would be a challenge to untangle the cause-and-effect relationship between sleep and nutrition. "There may be a third factor that impacts both of those," he said. "Or the relationship could be reversed, such that people who eat less fall asleep earlier."
Aschbacher says both scenarios are plausible: first, that a certain type of person is "overall more focused" on healthy sleep and nutrition, or second, that sleep directly affects the next day's food intake.
"The second is more relevant to Jawbone, because it's what we are more likely to help people change," she told HuffPost.
She cited biological mechanisms that could explain that scenario, like "how poor sleep is known to change the secretion of hormones -- like leptin and ghrelin -- that cause a person to feel hungrier."
For many adults, failing to go to sleep at a consistent hour every night may just be a result of forgetting to do so -- after all, Mom and Dad aren't around to enforce bedtime. But perhaps a buzzing wristband can do the trick.