Don’t Blame the Biscuit: Your Brain is Hacking Your Hunger
If you’ve ever found yourself polishing off a bag of crisps despite feeling physically incapable of another bite, don’t blame your appetite, blame your wiring. It’s the ultimate snack conundrum: why does the craving remain even when the tank is full? The good news – it’s not necessarily your fault. Researchers at the University of East Anglia (UEA) have discovered that our brains are essentially running a hidden snack script that doesn’t care about your full stomach, making that “one last treat” feel less like a choice and more like a neural command.
A new study has revealed that the human brain continues to fire off high-voltage excitement in response to tempting food cues, even after a person has eaten more than enough. In a world saturated with ultra-processed food (UPF), snack adverts and fast-food restaurants, these findings help explain why maintaining a healthy weight often feels like an uphill battle.
Blame the brain if you can’t stop snacking
Lead researcher Dr. Thomas Sambrook, from UEA’s School of Psychology, suggests we might be being a bit too hard on ourselves.
“Obesity has become a major worldwide health crisis. But rising obesity isn’t simply about willpower – it’s a sign that our food-rich environments and learned responses to mouth-watering cues are overpowering the body’s natural appetite controls,” Dr. Sambrook says.
To get to the bottom of the ‘dessert stomach’ phenomenon, researchers monitored 76 volunteers using Electroencephalograms (EEG) brain scans as they played a reward-based learning game involving sweets, chocolate, crisps, and popcorn. Not a bad way to earn a crust!
Halfway through the task, participants were given a meal of one of the foods until they didn’t want another bite. According to the researchers, the participants were truly full and reported a “dramatically reduced desire” for the food, and their behaviour showed they no longer valued it.
But their brains told a different story.
A recipe for overeating
Even when the volunteers were completely full, electrical activity in the areas of the brain associated with reward continued to react just as strongly to images of the now-unwanted food.
“What we saw is that the brain simply refuses to downgrade how rewarding a food looks, no matter how full you are,” says Dr. Sambrook. “Even when people know they don’t want the food, even when their behaviour shows they’ve stopped valuing the food, their brains continue to fire ‘reward!’ signals the moment the food appears. It’s a recipe for overeating.”
The findings, published in the journal Appetite, suggest that our responses to food cues may work like habits – automatic, learned reactions forged over years of pairing certain foods with pleasure.
It’s not you, it’s your wiring
The study found no link between a person’s ability to make goal-directed decisions and their brain’s resistance to food “devaluation.” That means even people with excellent self-control can be undermined by automatic neural responses.
“If you’re struggling with late-night snacking or can’t say no to treats even when you’re full, the problem may not be your discipline – it may be your brain’s built-in wiring,” says Dr. Sambrook. “It’s really no wonder that resisting a doughnut can feel impossible.”
The research, a collaboration between UEA and the University of Portsmouthsuggests that next time you find your hand in the cookie jar after a three-course meal, you can officially blame your “well-worn script.”
