Lack of Sleep Causes Brain to Eat More
Multiple studies now support the fact that a lack of sleep changes brain activity and increases the urge to eat more. Sleep deficiency also produces the inclination to eat more high calorie foods.
Brain function studied
Research was conducted using functional magnetic resonance imaging (fMRI) in order to analyze the relationship between brain function and eating habits among 23 human test subjects.
The subjects were tested after having a good night’s sleep, and then tested after having a bad night’s sleep. The good night’s sleep consisted of enough sleep to feel fully rested and awake during the day, and the poor night’s sleep resulted in daytime sleepiness.
After the poor night’s sleep the subjects were found to have less activity in the frontal cortex of the brain, while having increased activity in the amygdala part of the brain.
Increased activity in the frontal cortex has been linked in other research with healthier eating habits, while more activity in the amygdala has been linked with eating more, weight gain and binge eating – especially high-calorie foods.
The researchers also found that those who had the most sleep deprivation had the greatest amygdala activity – indicating the urge to eat high-calorie foods becomes greater as our sleep becomes worse.
The researchers concluded that,
“These findings provide an explanatory brain mechanism by which insufficient sleep may lead to the development/maintenance of obesity through diminished activity in higher-order cortical evaluation regions, combined with excess subcortical limbic responsivity, resulting in the selection of foods most capable of triggering weight-gain.”
The findings of this study confirm a study last year by researchers from the Department of Neuroscience at Sweden’s Uppsala University. Here the researchers tested 12 healthy men who were studied with brain scans along with food cravings and appetite, and blood sugar testing, after a poor night’s sleep (sleep deprivation) and after a good night’s sleep.
In this study the researchers – using functional magnetic resonance imaging – found that sleep deprivation caused brain activity to increase in the right anterior cingulate cortex as the subjects watched images of foods.
The emotional part of the anterior cingulate cortex links to the amygdala – providing the association between the results of these two studies.
To provide confirmation of the link between increased activity in the anterior cingulate cortex, the researchers found that appetite scores among those with increased anterior cingulate cortex activity were higher than among those with less brain activity in that region.
Blood sugar affected
These brain-activity changes among the sleep-deprived subjects also resulted despite no difference in the subjects’ relative blood glucose levels, between the poor night’s sleep and the good night’s sleep testing. This indicates that the relationship between sleep and eating is not related to a change in blood sugar levels during sleep – but specifically on brain activity.
The researchers concluded:
“These results provide evidence that acute sleep loss enhances hedonic stimulus processing in the brain underlying the drive to consume food, independent of plasma glucose levels. These findings highlight a potentially important mechanism contributing to the growing levels of obesity in Western society.”
These studies confirm other research tying obesity and overeating to sleep deprivation.
So it looks like a start to any successful weight loss diet is a good night’s sleep.
Greer SM, Goldstein AN, Walker MP. The impact of sleep deprivation on food desire in the human brain. Nat Commun. 2013 Aug 6;4:2259.
Benedict C, Brooks SJ, O’Daly OG, Almèn MS, Morell A, Åberg K, Gingnell M, Schultes B, Hallschmid M, Broman JE, Larsson EM, Schiöth HB. Acute sleep deprivation enhances the brain’s response to hedonic food stimuli: an fMRI study. J Clin Endocrinol Metab. 2012 Mar;97(3):E443-7.
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