Relation of reward from food intake and anticipated food intake to obesity: a functional magnetic resonance imaging study

Abstract

The authors tested the hypothesis that obese individuals experience greater reward from food consumption (consummatory food reward) and anticipated consumption (anticipatory food reward) than lean individuals using functional magnetic resonance imaging (fMRI) with 33 adolescent girls (mean age = 15.7, SD = 0.9). Obese relative to lean adolescent girls showed greater activation bilaterally in the gustatory cortex (anterior and mid insula, frontal operculum) and in somatosensory regions (parietal operculum and Rolandic operculum) in response to anticipated intake of chocolate milkshake (vs. a tasteless solution) and to actual consumption of milkshake (vs. a tasteless solution); these brain regions encode the sensory and hedonic aspects of food. However, obese relative to lean adolescent girls also showed decreased activation in the caudate nucleus in response to consumption of milkshake versus a tasteless solution, potentially because they have reduced dopamine receptor availability. Results suggest that individuals who show greater activation in the gustatory cortex and somatosensory regions in response to anticipation and consumption of food, but who show weaker activation in the striatum during food intake, may be at risk for overeating and consequent weight gain.

Figure 1

Example of timing and ordering of presentation of pictures and drinks during the run.

Figure 2

A. Saggital section of greater activation in the left anterior insula (−36, 6, 6, Z = 3.92, P uncorrected <.001) in response to anticipatory food reward in obese compared to lean subjects with B. the bar graphs of parameter estimates from that region. C. Sagittal section of greater activation in the Rolandic operculum (54, −12, 33, Z = 5.95, P uncorrected <.001) in response to consummatory food reward in obese compared to lean subjects with D. the bar graphs of parameter estimates from that region. Note: *p<.05; **p<.001.

Figure 3

A. Axial section of greater activation in the left temporal operculum (TOp; −54, −3, 3, Z = 3.41, P uncorrected <.001) and in the right ventrolateral prefrontal cortex (VLPFC; 45, 45, 0, Z = 3.57, P uncorrected <.001) in response to anticipatory food reward as a function of BMI. B. Coronal section of greater activation in the parietal operculum (−54, −3, 3, Z = 3.49, P uncorrected <.001) in response to consummatory food reward as a function of BMI with C. the graph of estimates from that region. D. less activation in the caudate nucleus (−12, 3, 27, Z = 3.57, P uncorrected <.001) in response to food receipt as a function of BMI with E. the graph of parameter estimates from that region.