It’s no secret that many people struggle with both diet and sleep. Over two-thirds of Americans are overweight and obese, and an estimated 30 percent of American workers fail to get enough nightly slumber, a figure that equates to roughly 41 million people. The consequences of these poor lifestyle choices are blatantly obvious – eating junk food leads to weight gain, and a lack of sleep leads to recurring trips to the coffee maker. What is not quite so apparent is the relationship between sleeping patterns and weight. Skimping on sleep not only makes you groggy in the morning, but makes maintaining a thin figure even more challenging.
Sleep Less, Eat More?
To counter the lethargy caused by poor sleep, many people instinctively turn to foods that can provide a quick energy boost. Unfortunately, these foods are often lacking in nutritional value, serving to add little more than empty calories to the body. Further compounding this problem is that insufficient sleep can throw your hormones out of whack. Simply put, hormones are cells used by the body to transmit messages to other types of cells.
Among your body’s many hormones are ghrelin and leptin, both of which have a major influence on your appetite. The former makes you want to eat, while the latter puts the brakes on your food cravings. An adequate amount of sleep is needed to maintain a proper balance of these two hormones. When sleeping, leptin increases inside the body, allowing it to inform the brain that the body has sufficient reserves of energy. At the same time, ghrelin’s presence diminishes after we fall asleep.
Failing to get enough sleep stymies the production of leptin, while keeping an excessive amount of ghrelin in your system. As a result, the brain doesn’t receive the “don’t eat” message from your leptin hormones. This causes the brain to mistakenly believe that the body is running low on stored energy, and therefore needs to eat more food. The brain then stimulates the body’s appetite in order to get these additional calories.
Researching Sleep, Appetite and Weight
The connection between poor sleep on appetite has been the subject of a fair number of studies. One such example is a report produced by Germany’s University of Lübeck, which was published in the June 2011 issue of The American Journal of Clinical Nutrition. For this study, a set of fourteen male participants were asked to sleep for twelve hours straight. This same group was required to go completely forego sleep the following night. After surviving a night without sleep, the researchers allowed their subjects to feast from lavish afternoon buffet.
During the day, researchers observed the men’s energy expenditure, or the amount of calories their bodies burned from performing routine functions. When functioning on zero sleep, the men’s energy expenditure rate declined by 5 percent. After meals, this figure that quadrupled to 20 percent.
Aside from reducing the rate at which the body expends calories, research has also found that a lack of sleep goes hand-in-hand with greater calorie consumption. This was the conclusion of a study released by Columbia University in March 2011, which observed a total of twenty-six adults. This group was divided evenly between men and women, and every volunteer was of normal weight.
Each participant was required to follow two distinct sleeping schedules during the study. One schedule allowed the subjects to sleep for nine hours nightly, while the other restricted them to just four. The subjects were asked to stick with a given schedule for six days, before switching over to the other pattern for the same amount of time. For some volunteers, the nine-hour schedule came first; for others, the opposite was true. Finally, the study’s authors recorded how much their subjects ate throughout the day.
When reviewing their data, the Columbia researchers found that fewer hours of sleep impacted the dietary habits of both men and women. Specifically, men subsisting on four hours sleep consumed an average of 263 additional daily calories. For women, the effect was even greater, as female participants ate an extra 329 calories per day when getting less sleep.
Sleep may also dictate what type of weight you shed overnight. The University of Chicago conducted a study which measured weight loss in ten overweight males. Upon completion, this research was published in the October 5th, 2010 issue of the Annals of Internal Medicine. The men were placed on a healthy diet, causing them to lose a significant amount of weight.
Similar to the Columbia University study, these subjects were asked to follow two separate sleeping patterns, both of which lasted for exactly two weeks. During the first 14 day period, participants were allowed 8 ½ hours for sleeping. As a result, the men slept an average of 7.25 hours per night. The second 14-day period set aside only five and a half hours for sleep, reducing the average amount of nightly sleep to 5 hours and 14 minutes.
Despite maintaining the same diet through the duration of the study, the shift in sleeping patterns significantly impacted the men’s weight loss. The average amount of pounds lost did not change when the men started sleeping less; under both schedules, the subjects dropped an average of 6.6 pounds over 14 days. What did change was the type of weight the men shed; when getting a greater amount of sleep, the lost weight was almost evenly distributed between fat (3.1 pounds) and fat-free body mass (3.3 pounds). This ratio became greatly imbalanced with during the second two-week period, with losses in fat and fat-free body mass averaging 1.3 and 5.3 pounds, respectively.
Another important finding involved the subjects’ levels of ghrelin. When sleeping over 7 hours per night, the men’s ghrelin levels measured in at 75 nanograms per liter (ng/L). The change in sleeping patterns lead to subsequent spike in ghrelin, with the average reading climbing to 84 ng/L over the second 14-day timeframe.
Simple Guidelines for Sleeping
While everyone needs sleep, many people still find themselves getting to bed at a very late hour. For those looking to correct this habit, the National Sleep Foundation has outlined some basic tips that could prove useful.
- Regardless of how full your schedule may be, make a conscious effort to get seven to nine hours of sleep each night.
- Avoid exercising as your bedtime approaches. Try to wrap up your exercise regimen three hours before going to bed.
- Refrain from drinking caffeinated or alcoholic beverages shortly before hitting the hay. The stimulating effects of caffeine can keep you awake for quite a while, whereas alcohol can also interfere with healthy sleeping patterns.