How sleep loss stirs junk food cravings

Kathleen Blanchard's picture
More information about how sleeplessness makes us crave junk food.

Now researchers know more about what happens in the brain that stirs our desire for junk food when we lose sleep.

Too little sleep activates primal brain structures

UC Berkley researchers used functional MRI (fMRI) scans to find out what we already know - that we don’t make the best decisions when we haven’t had a good night’s sleep. The same is true for food.

Our brain switches gears when we get too little sleep. The MRI scans showed less activity in the frontal lobe of the brain that governs decision making and increased activity in the deep regions of the brain that crave rewards.

The finding also lends insight into why lack of sleep is linked to obesity. We also seem to be hungriest when we’re tired from getting to bed too late and getting up too early or after a night of interrupted sleep.


Matthew Walker, a UC Berkeley professor of psychology and neuroscience and senior author of the study published in the journal Nature Communication said in a press release, “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.”

Past studies have found a link between sleep deprivation and cravings for sweet or salty foods. The current study explains how a sleepless night alters our brain mechanisms to make poor food choices.

The researchers scanned 23 healthy adults after a poor night’s sleep and again when they had slept well to reach their conclusions.

The study participants were given 80 different food images that ranged from high calorie burgers, pizza and donuts to low-calorie fruits and vegetables.

With little sleep, the study participants chose the high calorie foods.

The less we sleep, the more we eat. The finding once again shows us just how important a good night’s sleep is for tackling obesity. Maybe it is time to start allowing a mid-day nap in the workplace since too few of us are getting the recommended 7 to 8 hours of sleep each night. Too little sleep makes us crave junk food and it's our brain's fault.


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