Sleep a little earlier and save your diet.
We've all been there: Pull a few late-nighters, and suddenly you can't stop eating everything in sight.
Now, there just might be a scientific reason for your hungry, sleep-deprived moments. Research from scientists at Northwestern University's Feinberg School of Medicine suggests that your brain is more sensitive to food smells when you haven't slept in a while.
Their study involved the carefully-controlled food and sleep patterns among a group of volunteer participants. First, participants were allowed only four hours of sleep and were even repeatedly woken up throughout the night. (We're not sure why anyone would volunteer for this experiment, but...we digress.) Over the course of the next day, these same participants were asked to inhale odors like potato chips, cinnamon rolls, and non-edible items like fir tree samples. Their brain behavior was observed through a functional MRI scan.
A few weeks later, the participants were invited back for another round of food-smelling—but this time, they were allowed a full 8 hours of sleep the night before. Interestingly, they showed less brain activity in response to those same foods than they did when observed a few weeks earlier operating on less sleep. There was no spike witnessed with the non-food odors.
"When tired, participants showed greater brain activity in two areas involved in olfaction—the piriform cortex and the orbitofrontal cortex—in response to food smells than they did when well rested. That spike wasn't seen in response to nonfood odors," study co-author Surabhi Bhutani told Science News.
So, while it's unclear why there's a connection between the amount of sleep the study participants had and their reaction to food smells, there almost certainly is one. And it could definitely be one of the reasons your current diet's not working out too well.
Personally, we'll be climbing into bed a few hours earlier tonight.