Hitting the fast food drive-thru too often? Picking up too many sugar- and fat-filled snacks? Maybe it’s not weak character that’s driving those bad choices – several studies indicate that a poor night’s sleep could be a major contributor.
A study from the University of California at Berkeley scanned the brains of two dozen study participants after both a good night’s sleep and a bad one.
After disturbed sleep, there was increased activity in the depths of the brain, which is generally associated with rewards and automatic behavior. The frontal lobes, just behind and above the eyes, which help provide self-control, were less active.
According to Matthew Walker, one of the authors of the Berkeley study, “What we have discovered is that high-level brain regions required for complex judgments and decisions become blunted by a lack of sleep, while more primal brain structures that control motivation and desire are amplified.”
So inadequate or poor-quality sleep weakens our self-control. To make it even worse, researchers said that sleep-deprived participants displayed greater cravings for high-calorie junk food – and the more sleep-deprived they were, the greater were their cravings.
By contrast, when they were well-rested, the same people were better able to resist temptation. Proving perhaps that a good night’s sleep builds character — or at least that we can’t think clearly without it.
That study relating lack of sleep to junk-food cravings is just one of several recent research reports linking poor sleep to poor dietary choices. Here’s more:
A study of 13,284 teenagers found that those who slept poorly also made poor decisions about food. The sleepy teens ate more junk food and less healthy food, according to Lauren Hale, PhD, associate professor of preventive medicine at Stony Brook University School of Medicine in Stony Brook, N.Y.
“While we already know that sleep duration is associated with a range of health consequences, this study speaks to some of the mechanisms, i.e., nutrition and decision making, through which health outcomes are affected,” Hale said.
That relationship between poor sleep and poor food choices was also highlighted in a study in Sweden, published in ScienceDirect, that found that at a buffet, sleep-deprived individuals were more likely to load up their plates.
And it’s not only when tired people are faced with easy-to-get prepared foods like fast food and groaning buffet tables that they make poor food choices.
Another Swedish study showed that men who were sleep-deprived bought an average of 9 % more calories when food shopping than men who’d had a good night’s sleep.
The tendency to eat more after poor sleep often has been blamed on the so-called “hunger hormone” ghrelin. But these latest studies suggest that it’s simple self-control that is most important in causing the sleep-deprived to over-indulge, as identified in the UC Berkeley study.