The Reason You Can't Resist Junk Food

April Daniels Hussar,SELF magazine

Yet another reason to break your staying-up-late-waking-up-early cycle: Sleep deprivation doesn't just make you cranky, it makes you crave junk food!

According to data presented at the annual Associated Professional Sleep Societies meeting this week, researchers at St. Luke's-Roosevelt Hospital Center and Columbia University in New York performed functional magnetic resonance imaging (fMRI) brain scans on 25 men and women who, for five days in a row, had either been restricted to five hours of sleep a night or allowed to sleep up to nine hours. While performing the fMRIs, researchers showed the participants images of healthy and unhealthy foods.

Related: Shed Pounds Without Starving

Guess whose brain "reward centers" lit up, so to speak, when viewing photos of junk food, like donuts and cheeseburgers? That's right -- the sleep-deprived people.

"The same brain regions activated when unhealthy foods were presented were not involved when we presented healthy foods," the study's principal investigator, Marie-Pierre St-Onge, Ph.D., of Columbia University Medical Center, said in a statement. "The unhealthy food response was a neuronal pattern specific to restricted sleep. This may suggest greater propensity to succumb to unhealthy foods when one is sleep-restricted."

So, you're more likely to crave -- and eat -- junk food when you're sleep-deprived. And this doesn't surprise St-Onge, who found in a previous study that sleep-deprived people did indeed consume more fatty and unhealthy foods; this new study shows the accompanying brain activity, she explains. "Reducing sleep increases food intake," she tells HealthySELF, "and now we have the neurological components that explain this."

Related: Shed Pounds Without Starving


But why would it be that sleep-deprived people are less interested in healthy foods (like fruits, vegetable, yogurt, salad and trail mix) than "junky" foods (bacon cheeseburger, pepperoni pizza, donuts, candy and potato chips)? St-Onge explains that sleep deprivation reduces your cognitive control, while at the same time enhancing the desire for instant gratification. "When you're fatigued, you tend not to think, 'Is this what I should be eating right now?'" she says. "You just think, 'I'm tired and this smells good!' You can't deal with an additional battle within yourself."

Also, St-Onge notes, junky food can give you the quick burst of energy "pick-me-up" you might be craving when you're lacking in sleep -- a temporary, but appealing, fix.

St-Onge points out that if you break your diet in a sleep-deprived state, you're more likely to give it up on it altogether (for example, you might say to yourself: "Well, I already had a chocolate muffin today, so..."). But whether you're dieting or just trying to stay healthy, getting enough sleep is vital. As St-Onge says, "If you're trying to control or manage your weight, walking around sleep-deprived is not a good idea."

Related: Yoga Moves for Flat Abs

Need some help getting the zzz's you need to stay healthy and resist junky treats? Joseph M. Ojile, M.D., founder and CEO of Clayton Sleep Institute in St Louis, Mo., shared these top tips with HealthySELF for getting a good night's sleep:

- As much as possible, stick with a consistent bedtime and wake-up time.
- Avoid excessive time in bed or napping.
- Eliminate pre-sleep habits that invoke hyper-arousal (no more bedtime pillow fights!).
- Avoid caffeine within several hours of bedtime and alcohol at bedtime.
- Reserve your bed for sleep and sex.
- Remove technology from your bedroom: TV, computer, iPad, iPhone, e-readers, etc.
- Exercise in the late afternoon.


More from SELF:
5 Simple Steps to Cellulite-Free Skin
3 CrossFit Total-Body Workouts
50 Healthiest Snacks
6 Secrets to Firing Up Your Metabolism