They found that the brain was left wanting more while eating ice cream in the same way as a person who regularly uses cocaine.
Their study, published online in the American Journal of Clinical Nutrition, appears to add weight to previous studies that people can be left feeling "addicted" to some foods.
Dr. Kyle Burger, from the Oregon Research Institute, said overeating "high-fat" or "high-sugar" foods appeared to change how the brain responded and in turn downgraded the mental "reward."
"This down-regulation pattern is seen with frequent drug use, where the more an individual uses the drug, the less reward they receive from using it," said Burger, the study's co-author.
"This tolerance is thought to increase use, or eating, because the individual trying to achieve the previous level of satisfaction.
“Repeated, overconsumption of high-fat or high-sugar foods may alter how the brain responds to those foods in a way that perpetuates further intake."
He added, "The data supports the theory that overeating such foods may result in changes in how the brain responds to those foods in a similar fashion seen in drug addiction."
In their study, 151 teenagers, aged 14 and 16, were fed real chocolate milkshakes made with Häagen Dazs ice cream.
The researchers had already conducted interviews with the teenagers, all of whom were of "healthy weight," about their recent eating habits and how much they craved certain foods.
Their brains were then scanned with a Functional Magnetic Resonance Imaging Machine (fMRI) while being shown a picture of a milkshake before being given a physical shake.
The study found that all the participants wanted the real shake, but those who ate the most ice cream over the previous few weeks enjoyed it less.
Burger explained that this was the same reaction that a drug addict felt, because despite increased cravings, pleasure that should be sent to the brain was being blunted.
This, he said, was possibly due to the brain releasing lower levels of the chemical dopamine.
When they analyzed the fMRI scans, the study found the teenagers who had eaten the most ice cream had experienced a similar effect. As a result, they felt they had to eat more to enjoy the same feelings of euphoria.
"You could be continually trying to match the earlier experience," he told The Daily Telegraph. This, he added, would lead to bigger portion and weight gain.
While it was unlikely that people became “addicted to ice cream per se,” the findings appeared to suggest that ice cream had "addictive-like properties," he added.
“Some individuals may frequently eat ice cream or other high-fat/high-sugar foods and show no characteristics of addiction, while others may develop an addictive like relationship with food,” he said.
“Some people will try smoking, drinking or gambling, but not develop an addiction. We often joke and say ‘I wouldn't say food is addictive, but I hear some people can't live without it’.”
However, Burger said the findings also provided further explanation to why people become fat from ice cream. It adds to previous studies that linked junk food and addiction.
He said his study was a small piece amid a growing body of literature “regarding the neural consequences of overeating.”
“Repeated consumption of these types of foods also can provide excess calories,” he said.
“This could mean that high-fat or high-sugar food contributes to unhealthy weight gain in two ways, altering the brain while providing excess calories.”
He said more research was needed because the assessment of the brain responses to only one on food item and the reliance on self-reported intake.
From the March 6, 2012, Prepared Foods' Daily News.