To help test this, researchers presented participants with foods falling into three categories: mostly fats, mostly carbs, or a combination of the two. They would then attempt to pay for these foods in an auction-like exercise, all while having their brain scanned using functional magnetic resonance imaging.
Results showed participants were more willing to pay more for the foods combining fats and carbs, which researchers said was reflected in stimulated activity in the brain's dorsal striatum and mediodorsal thalamus, key areas that deal with assessing rewards.
Although it's great for your brain, it can lead us to eating a lot more than we should.
The study points out foods high in both carbohydrates and fats rarely exist in nature, with the exception of breast milk. Researchers say breast milk averages about 3.5 percent fat and 7 percent carbohydrate, but standard processed snack foods contain closer to 24 percent fat and 57 percent carbohydrates.
"In the modern food environment that is rife with processed foods high in fat and carbohydrate like donuts, French fries, chocolate bars, and potato chips, this reward potentiation may backfire to promote overeating and obesity," said Small.