THE DETAILS: Researchers from several Boston-area institutions surveyed 542 truckers (chosen because they often work long hours and have a variety of factors—including irregular shifts, mealtimes, sleep patterns, and accommodations—that influence their sleep duration and quality) working in eight U.S. trucking terminals. What they found was that those truckers who said they got enough sleep to "feel rested upon waking up" reported eating daily, on average, about three servings of fruits and vegetables, less than one serving of a sugary drink, and less than half a serving of a sugary snack. Truckers who said they got insufficient sleep, on the other hand, reported eating just two servings of fruits and veggies, slightly more than one sugary drink, and nearly one sugary snack a day—essentially, a less healthy diet. The researchers conclude: Adequate sleep is associated with more healthful food choices.
WHAT IT MEANS: The less sleep you get, the hungrier you get—and the more likely you are to make bad food choices. "Recent research from both laboratory-based and epidemiological studies indicates that sleep restriction is associated with increased hunger and appetite," says lead study author Orfeu M. Buxton, PhD, an instructor in medicine at Harvard Medical School and an associate neuroscientist at Brigham & Women's Hospital in Boston.
To explain the "why" behind his own study findings, Buxton cites recent research in which people without ample sleep for two nights exhibited elevated appetite and hunger that was strongly linked to increased ghrelin (a chemical hunger signal from the stomach) and lower circulating leptin (a chemical satiety signal from the body's fat cells), which together drive appetite. In other words, lack of sleep doesn't just make you less able to resist temptation or so exhausted you generally slack on your diet—it raises hunger chemically, and so, raises your risk of weight gain, obesity, diabetes, hypertension, and heart disease.
Here's how to get more sleep, so you'll be primed to eat healthy:
• Aim for seven or more hours of sleep a night. A very large study of adults found that those who sleep at least seven hours per night have the lowest risk of mortality—which, in light of the current study's findings, may indicate a more healthful diet, too. While people's sleep needs do vary, seven hours seems to be a good goal for most people.
• Work out in the late afternoon, if possible. Exercising regularly is a key to excellent health and weight control, but working out right before bed can lead to a poor night's sleep—which won't do your weight any favors. What happens is this: Your body temperature rises while you work out and can take as long as six hours to begin to drop. Because cooler body temps are associated with sleep onset, it's important to allow your body time to cool off before sleep. The National Sleep Foundation recommends exercising at least three hours before you hit the mattress, and ideally, in the late afternoon.
• Finish eating at least two hours before bedtime. According to the National Sleep Foundation, eating or drinking too close to bedtime can stimulate your system and make it difficult to both get to sleep and control your weight.
• Swear off the Starbucks. Not only are those mocha lattes murder on your waistline, but also caffeine is a stimulant that can affect some people up to 12 hours later, warns the National Sleep Foundation. To improve the quality of your sleep and trim your diet of excess calories, avoid caffeine within six to eight hours of going to bed. Once you get on a good sleep schedule, you can experiment to see how close to bedtime you can ingest caffeine without staying awake.
• Just say no to a nightcap. Like those mocha lattes, alcohol is both calorie-dense and a sleep hazard. Although many people think of alcohol as a sedative, says the National Sleep Foundation, it actually disrupts sleep, causing nighttime awakenings and poor sleep quality. Avoid consuming alcohol before bedtime to sidestep the calories and the sleep issues.