Food preferences are not necessarily innate.a study A paper published Wednesday in the journal Cell Metabolism suggests that eating fatty and sugary snacks alters brain activity, creating a persistent preference for these less-healthy foods.
In this study, researchers at Yale University and the Max Planck Institute for Metabolism in Germany fed one group of participants high-fat, high-sugar yogurt twice daily for eight weeks, and another group on low-fat, high-sugar yogurt. I gave him low sugar yogurt. Both groups otherwise continued their normal diets.
Finally, the group evaluated puddings with different fat concentrations and apple juice with different sugar levels. The group that ate the high-fat, high-sugar yoghurt did not like the low-fat pudding, and did not want the low-sugar apple juice as much as the first.
Participants then underwent an MRI scan while drinking a milkshake. Scans showed that snacks increased brain activity in the group that ate high-fat, high-sugar yogurt, but not in the other groups.
Researchers concluded that fatty, sugary snacks activate the brain’s dopamine system, giving people a sense of motivation and reward.
“Let’s say a new bakery opened next door to your place of work and you stopped by every morning and started eating scones. That alone would allow you to rewire the basic basic dopamine learning circuits,” says the study. Dana Small, senior author and director of the Center for Modern Dietary and Physiological Research at Yale University School of Medicine, said.
This is an intuitive idea for anyone who has developed the habit of eating dessert often.
Small meals have such a strong impact on brain activity that dopamine signals are fired even when you expect to eat foods high in fat and sugar, such as when you walk past a bakery or smell pastries. There is likely to be.
“It tells us how sensitive we are to our food environment, and how the food environment can actually change our behavior.
Sugary and fatty foods alter brain activity
The new study was small, involving only 49 people, and all were healthy, not smoking, not taking drugs, and not overweight or obese. Overall, the participant did not gain significant weight over his eight weeks.
According to Small, the study is the first to demonstrate in humans that even small dietary changes can rewire brain circuits and increase long-term risk of overeating and weight gain.
Previous studies have shown that obesity change people’s brain activityand people have a natural aversion to bitter foods and tend to prefer sweet foods.
On the other hand, experiments with rodents have shown that high-fat, high-sugar foods Rewiring dopamine neurons and lead to overeatingBut scientists didn’t know much about how human eating habits influence food preferences.
“We now have enough evidence to be fairly confident that this happens, and that it happens in multiple species,” Small said.
Susan Swithers, a behavioral neuroscientist at Purdue University who wasn’t involved in the study, said people may develop a preference for foods they eat regularly and then gravitate towards them.
“People think we eat what we like, but in reality we like what we eat.
There may even be a biological reason why people prefer fatty, sweet foods, according to Garrett Steuber, a professor of neuroscience at the University of Washington who was not involved in the study. People today could instinctively share those preferences, as they likely wanted energy-dense foods high in fat and fat.
“Thousands of years ago they were very sparse and not very widespread, but the fact that they are now in almost everything we eat works against biology. It is.
How much do food preferences change over time?
One question that remains unanswered, says Small, is whether people can change their tastes once they’ve become accustomed to a high-fat, high-sugar diet.
“Maybe if we gradually reduce fat to more acceptable levels, we can eventually change our tastes in a more sustainable way. But I don’t think we know that. No,” she said.
a 2012 study After routine exposure to unsalted soups, people have shown that they eventually like those soups as much as the salty versions. He said it could also work.
But Stuber said it’s hard for people to forget that fatty, sweet foods are delicious.
“Even if you just stop presenting something worthwhile to people, the memory doesn’t go away,” he said.
He added that once you dislike a particular food, that preference can last a lifetime.
“Think of food poisoning, for example. You can eat a certain food and get sick, and you will develop a permanent and long-term aversion to that food,” Staber said.
