Lack of Sleep May Lead to Weight Gain
Both sleep deprivation and weight gain are common in the United States, with the Center for Disease Control estimating that as many as one third of Americans get less than seven hours of sleep per night and one third of Americans are obese. A recent study suggests that the two may be related, finding that sleep loss is linked to higher levels of a hormone that increases desire for high calorie foods and leads to weight gain.
Participants in the study included 14 healthy men and women in there twenties. The participants underwent two trials aimed at determining if there is a connection between weight gain and sleep loss. The first trial was a four-day period spent at a clinical research center, during which they were required to spend 8.5 hours in bed every night, and received an average of 7.5 hours of sleep per night. The second trial was another four-day period, during which they spent 4.5 hours in bed and received an average of 4.2 hours of sleep per night.
All of the participants ate three times a day, at 9 a.m., 2 p.m., and 7 p.m. during the two trial periods. The researchers measured levels of ghrelin (which increases appetite) and leptin (also known as the “satiety hormone,” as it informs the body when it’s full). They also measured blood levels of endocannabinoid 2-arachidonoylgycerol (2-AG), which is a chemical signal that increases the pleasure and satisfaction received from eating. 2-AG is the same chemical signal triggered by marijuana use and levels are typically low overnight, increasing throughout the day until peaking in the early afternoon then decreasing.
The researchers found that 2-AG levels rose 33% higher after restricted sleep when compared with longer sleep times. The levels also peaked 1.5 hours later, at 2 p.m. instead of 12:30 p.m., and stayed elevated until 9 p.m. Additionally, the participants reported significant increase in hunger levels after restricted sleep, particularly after the second meal of the day, as well as a greater desire to eat.
On the fourth day of both trial periods, the participants were offered snack foods less than two hours after eating a large meal. During the restricted sleep trial, they ate more food and chose foods that contained 50% more calories and twice the amount of fat as they did during the longer sleep trial.
The researchers concluded that the elevated levels of 2-AG throughout the day are directly linked to both less sleep and higher caloric consumption.
Researchers from the University of Chicago conducted the study. It was published on February 29, 2016, in the journal SLEEP.
Weight gain isn’t the only danger associated with lack of sleep. Previous studies have linked not getting enough sleep with faster cognitive decline, increased blood pressure, and increased risk of cardiovascular disease. Some methods to try to improve your sleep include eating less high fat foods, eliminating “blue light” (like the light from your phone) just before bed, and increasing exercise levels.