The Real Reason We Want Junk Food when We're Tired

By YouBeauty.com | Healthy Living – Thu, Aug 8, 2013 9:33 PM PHT

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Your tired brain just can't say no.Sleep deprivation can put a big damper on every aspect of our lives. From making us more irritable and changing the way we interact with loved ones to ruining our focus and productivity at work to aging our skin, skimping on shut-eye has a myriad of negative health, beauty and social consequences.

MORE: How Lack of Sleep Ages You

We already knew from a May 2011 study that less sleep leads to more snacking and increased consumption of carbs as opposed to healthy proteins and fats. Now, an August 2013 study from UC Berkeley, which examined the brain regions that control food choices, adds a new dimension to this connection by pinpointing the neural circuitry at work when we choose to reach for pizza and bagels instead of whole grains and vegetables when we're sleepy.

The participants (23 healthy, young adults) were shown a series of 80 food images, including a range of low-calorie, high-calorie, healthy and unhealthy items and were asked to rate their desire for each. Researchers scanned their brains (using fMRI) during this selection process after a normal night's sleep. Then, they repeated the process after a sleepless night.

QUIZ: Are You Getting Enough Sleep? 

After a sleep-deprived night, burgers, pizza, donuts and other high-calorie choices were more popular among participants. The scans showed that the brain's frontal lobe, the control center responsible for complex decision-making, was impaired when it was deprived of a good night's sleep. On the flipside, they showed increased activity in the brain's reward centers. These two activities combined led participants to choose unhealthier foods than they normally would after a solid night's sleep. 

So when you're tired and bleary-eyed, your ability to make smart decisions goes out the window, and instead you give in to your impulsive desire for a reward. Which in this case is that glazed donut or bacon cheeseburger with fries that you normally would stop yourself from inhaling.

MORE: Build Better Sleep Habits 

So what's the takeaway? Matthew Walker, a UC Berkeley professor of psychology and neuroscience and senior author of the study, points to improving sleep habits as a way to control weight. "Getting enough sleep is one factor that can help promote weight control by priming the brain mechanisms governing appropriate food choices," he says. And not only will snoozing help you make better dietary choices, but you'll also wake up feeling (and looking) healthier. We can't see any negative consequences coming from that.

- by Amy Marturana 

source: http://ph.she.yahoo.com/blogs/healthy-living/real-reason-want-junk-food-were-tired-133300273.html