In the first one, 91 people were place in a fMRI scanner and asked to rate how much they would like to eat different foods: a cookie, a yogurt, and brussels sprouts. In a second condition, the subjects were asked to now focus on the healthiness of the food.
On average, this focus shifted participants’ preference, and this regulatory success correlated with the size of two areas in the prefrontal cortex: the ventromedial and dorsolateral regions, which have been previously associated with cognitive evaluation, behavioral inhibition, and decision-making.
In a second study, 32 participants were shown images of highly lapatable and caloric foods ( a slice of chocolate cake, a cheese sandwich, and a croissant) and asked how much they would be willing to pay to eat them. In a second condition, the subjects were asked to distance themselves from their craving using the method of their choice.
Again, regulatory success correlated with the size of the same two brain regions.
Source: Schmidt et alia (2018)