WHY THE JUNK FOOD CRAVINGS?
Have you ever had a late night out and woken up craving a salad? Didn’t think so. What’s more likely is you went for something with a little more fat or starchy carbs — the foods that we know accelerate weight gain and associated diseases like diabetes.
Studies show cravings for sugary sweets, heavy carbs and salty snacks increase by more than 30 per cent when you’re tired, compared with food choices you make when you’ve had eight hours sleep. But why do we lust after these foods?
It seems we physically ‘switch off’ our better judgement when we’re tired. A research team at the University of California scanned people’s brains while they were viewing food items — once when they’d had a full night’s sleep, and once when they were sleep deprived. The team then rated how much the participants desired each food. It discovered that the rational control regions at the front of the brain, which normally keep our hedonistic food desires in check, had shut down. Worse still, the more primal, deep-brain structures that drive impulsive decisions were revved up in response to desirable food images.
Without sleep, your body shifts to a more primitive pattern of brain activity that favours uncontrolled impulsivity, making you reach for a giant muffin rather than healthy leafy greens.