Two new studies suggest a link between sleep-deprivation and obesity. A new study at UC Berkeley has shown that food choices change for the worse after a sleepless night. According to the study published in the journal Nature Communications in August, sleep deprivation makes us more likely to choose junk food over healthier choices.
Using functional magnetic resonance imaging (fMRI), researchers scanned the brains of healthy young adults after a normal night’s sleep and then again after a sleepless night. They asked the participants to rate their desire for 80 food images shown to them ranging from healthy to unhealthy foods. The fMRIs showed that the frontal lobes, where complex decision-making takes place, in sleep-deprived brains were blunted, while deeper brain centers that respond to reward had greater activity. Participants favored unhealthy foods, especially high-calorie foods, when they were sleep-deprived.
Matthew Walker, senior author of the study, said, “high-calorie foods also became significantly more desirable when participants were sleep-deprived. This combination of altered brain activity and decision-making may help explain why people who sleep less also tend to be overweight or obese.”
Meanwhile, another study at the University of Chicago has demonstrated that sleep-deprived, overweight adults who got an average of 96 extra minutes of sleep per night, cut their cravings for sweet and salty junk food by 62 percent and reduced their appetite by 14 percent overall.
At the beginning of the study, published in the journal Appetite in September, participants reported sleeping less than 6.5 hours per night. The researchers gave them tips and instructions for sleeping longer and increased their sleep average by 96 minutes (1.6 hours), which is close to the optimal 8 hours a night. Participants reported being less hungry and having less craving for salty and fatty foods. They also reported that they had more energy and felt less sleepy.
We incur a metabolic cost when sleep deprived, said Chicago study author Dr. Esra Tasali. We compensate by eating more of less healthy foods. Extra sleep can curb temptation for junk food.
Though previous studies have linked poor sleep to greater appetites for sweet, salty and high-calorie food and weight gain these findings provide a specific brain mechanism explaining why food choices change for the worse following a sleepless night. Getting enough sleep is one factor in promoting weight control by priming the brain mechanisms that govern food choices.
“The God who gives His beloved sleep has furnished them also suitable food to sustain the physical system in a healthy condition.” Counsels on Diet and Foods, page 91
“Pure air, sunlight, abstemiousness, rest, exercise, proper diet, the use of water, trust in divine power—these are the true remedies. Every person should have a knowledge of nature’s remedial agencies and how to apply them. It is essential both to understand the principles involved in the treatment of the sick and to have a practical training that will enable one rightly to use this knowledge.” Ministry of Healing, page 127