Does this explain your sugar cravings? Study finds junk food physically rewires the brain to subconsciously crave more
Eating foods high in sugar and fat reprograms the brain to subconsciously prefer junk, a study suggests.
The study by scientists in Germany and the US measured the brain activity of a group that was fed a high-fat and sugar-rich dessert every day for two months.
They found that the brain responses of those given the pudding increased significantly after eight weeks – specifically activating the region responsible for motivation and reward and releasing dopamine.
The study’s authors concluded that the brain learns to subconsciously prefer and crave these fatty and sugary foods — even when people stop eating them.
Eating foods high in sugar and fat reprograms the brain to subconsciously favor junk snacks
The research team, from the Max Planck Institute for Metabolism Research in Cologne, West Germany, and Yale University, tested their hypothesis by selecting two groups of volunteers.
One group received a small pudding containing a lot of fat and sugar every day for eight weeks, in addition to their normal diet.
Another control group received a daily dessert that contained exactly the same amount of calories – but less fat.
The brain activity of the volunteers in both groups was measured before and during the eight-week experiment.
The research team, led by Dr Marc Tittgemeyer, noted that brain responses to sugary and high-fat foods in the group that ate the daily high-fat and sugary dessert increased dramatically after the eight weeks.
This increased activity mainly activated the ‘dopaminergic’ system – which releases the feel-good hormone dopamine in the area of the brain responsible for motivation and reward.
The release of dopamine gives us a sense of pleasure and the motivation to do something when we feel pleasure.
Every time we do something we enjoy — such as having sex, eating foods we like, or exercising — small amounts of dopamine are released in our brain.
However, vices such as drinking alcohol and using recreational drugs can also trigger the release of dopamine.
Dr. Tittgemeyer explained that our brains learn to prefer foods high in sugar and fat because of the cerebral activity — such as the release of dopamine — we experience when we eat them.
He said: ‘Our measurements of brain activity showed that the brain rewires itself through the consumption of potato chips and co.
“It unconsciously learns to prefer rewarding foods.
“Because of these changes in the brain, we will subconsciously always prefer foods that contain a lot of fat and sugar.”
Sharmili Edwin Thanarajah, another lead author of the study, added: ‘Our tendency to eat high-fat and sugary foods – the so-called Western diet – may be innate or arise as a result of being overweight.
“But we think the brain learns this preference.”
During the study, the volunteers who indulged in the daily high-fat and sugary dessert did not gain more weight than the control group.
Their blood values, including blood sugar and cholesterol levels, did not change either.
But dr. Tittgemeyer and his team believe that the preference for sugary and fatty foods in the test group will persist after the end of the study, as the brain forgets that it enjoys unhealthy foods.
‘New connections are made in the brain, which do not dissolve so quickly,’ says Dr. Tittgemeyers.
‘After all, the whole point of learning is that once you’ve learned something, you don’t easily forget it.’