The Form of Energy‐containing Food Alters Satiety and fMRI Brain Responses in Humans

Abstract

We examined the differences in satiety and brain activation after ingestion of apple in the form of juice, puree or slices.25 normal‐weight men had to eat a breakfast consisting of one of three apple products (cross‐over design): apple juice, puree or slices, each with the same caloric content. After breakfast, a fMRI session was conducted as follows: a 'liking' run consisting of viewing images (food and objects) whilst rating their appeal value, and a 'choice' run in which participants had to choose between two images of different categories (high‐fat/low‐fat sweet/savory). Measures of appetite were obtained by using visual analog scales at different times.Consumption of the three apple products led to differences in short‐term satiety, in the order slice > puree > juice. In the 'liking' run, the nucleus accumbens (NAcc), the orbitofrontal cortex (OFC) and the hypothalamus were more activated after consumption of apple juice vs. apple slices. Neural activity in the NAcc and OFC was positively correlated with hunger ratings after breakfast. In the 'choice' run, the OFC was more activated after the juice breakfast vs. slices, when subjects chose sweet images (rather than savory) and high‐fat images (rather than low‐fat). BOLD signal in the OFC measured when high‐fat foods were chosen was positively correlated with hunger ratings and ratings of 'expected pleasure to eat' reported after breakfast.These findings suggest that food form elicits differences in short‐term satiety, and leads to different responses to food cues in limbic (NAcc and OFC) and homeostatic (hypothalamus) regions underlying food intake.