Why skimping on sleep makes your brain crave sweets
- It’s a truism of the diet industry that getting too little sleep can make fatty, sweet foods more tempting. Now, researchers think they know why: Sleep loss influences the same smell-processing neural pathway that smoking marijuana does. “This is an exceptional study,” says Christian Benedict, a neuroscientist at Uppsala University in Sweden who has worked on the effects of sleep loss on metabolism but was not involved with the new research. Sleep deprivation has long been known to make people crave higher calorie foods. To find out how that process works, Thorsten Kahnt, a neurologist at Northwestern University’s Feinberg School of Medicine in Chicago, Illinois, took inspiration from studies linking sleep deprivation in humans to an increase in certain molecules in the endocannabinoid system, a complex network of neurotransmitters and receptors that, among other things, is affected by marijuana. Studies in mice have shown this system influences how the brain processes smells. And smell is a powerful driver of appetite—as illustrated by any gas station cinnamon roll shop.