- Western diets are rich in fat and sugar, and, until now, it’s been somewhat unclear if people’s preference for unhealthy foods is a result of genetic traits or a learned mechanism.
- A new study found that foods high in fat and sugar activate the dopaminergic system.
- This is a region in the brain responsible for motivation and reward.
Eating a lot of sugary, high-fat foods can teach your brain to crave sweets, according to new research.
The study, published in the journal Cell MetabolismWednesday, found that foods high in fat and sugar activate the dopaminergic system — a region in the brain responsible for motivation and reward.
As a result, the brain begins to seek out those unhealthy treats.
Western diets are rich in fat and sugar, and, until now, it’s been somewhat unclear if people’s preference for unhealthy foods is a result of genetic traits or a learned mechanism.
The new findings suggest that modern processed food choices are, in part, learned.
“Our study demonstrates that short-term daily consumption of high-fat, high-sugar snacks reduces preference for a low-fat food and rewires brain reward circuits to enhance response to palatable food,” the study’s co-lead Marc Tittgemeyer, PhD, a researcher at the Max Planck Institute for Metabolism Research, told Healthline.
To evaluate what motivates people to eat high-fat diets, the researchers tested different eating interventions and their health effects — including body weight, metabolic state, and general dietary pattern — in 49 individuals.
They gave half of the group a serving of high-fat, high-sugar pudding every day for eight weeks.
The other group was given a low-fat pudding for eight weeks.
The team measured each participant’s brain activity over the course of the study period.
They found that the brain’s response to sugary, fatty foods was especially active in the group that ate the high-fat pudding.
The dopaminergic system, in particular, lit up, suggesting that the brain’s reward circuits changed, causing the brain to prefer high-fat, sugar-rich foods.
Fat and sugar intake engage “the so-called dopaminergic midbrain, an area in the brain that is instrumental in regulating our reward responses and motivational drive,” explains Tittgemeyer.
At the same time, the brain produced less dopamine for low-fat foods, deprioritizing healthier options.
Those who ate the unhealthy pudding didn’t gain weight or experience changes in their blood sugar or cholesterol levels.
The researchers suspect that the group’s preference for high-fat, sugary foods would persist, potentially increasing their risk for overeating, and, eventually, weight gain and metabolic dysfunction.
“If we train our minds/bodies to always crave these types of foods, then it becomes that much harder to untrain our bodies to eat these types of foods,” Dana Ellis Hunnes, PhD, MPH, RD, a clinical dietitian, assistant professor at UCLA Fielding School of Public Health, and author of Recipe for Survival, told Healthline.
Over time, excess consumption of high-fat foods can increase one’s risk for heart disease, obesity, and diabetes, says Elaine Hon, RD, a clinical dietitian at Stanford Health Care.
People with genetic risks may be even more susceptible, the researchers noted. But, everyone — healthy or not — is susceptible to this.
“It also showed the possibility that even healthy weight individuals exposed to an unhealthy diet develop a reduced preference for low-fat foods and may adapt to overeating,” Hon said.
Tittgemeyer suspects that the brain networks, which evolved in a time when food was scarce, needed a way to eat beyond homeostasis, which simply satisfied energy consumption, in the event food was hard to come by.
“A reward mechanism is ideally suited for this, reinforcing intake for hedonistic reasons, and allowing to build up fat stores,” Tittgemeyer said.
Because the brain learns to reward unhealthy food choices, we’ll all unconsciously prefer foods that are rich in fats and sugar, the researchers say.
The biggest source of added sugars in the American diet is sugary drinks, says Hoy.
According to Tittgemeyer, the findings suggest it’s worth being intentional about our eating habits.
“Changing eating habits and reducing the availability of energy-dense snacks is pivotal to combatting obesity,” says Tittgemeyer.
Hunnes strongly recommends seeking out healthier, less-processed foods since our bodies crave more fatty-sugary foods the more we eat them.
“It’s easier to eat healthy foods when you have been eating them for some time than to change your diet to be healthier, as evidenced by this study,” Hunnes said.
Eating a lot of sugary, high-fat foods can teach your brain to crave sweets, according to new research. Foods high in fat and sugar activate the dopaminergic system — a region in the brain responsible for motivation and reward — causing the brain to seek out more unhealthy treats.