Dynamic Resting State Connectivity after a High-Sugar Meal—A Neural Signature of Feeding

The brain must integrate both external and internal feeding signals in an effort to maintain homeostasis and respond to the external food environment. Examination of the brain’s intrinsic connectivity, through resting state functional MRI (rsMRI), provides insight into how the brain integrates such signals. While this method has been used to identify differential connectivity associated with metabolic diseases (type 2 diabetes, obesity), fewer studies have tested differences in rsMRI following short-term manipulations, such as intake of a meal. Here, we studied the effect of a high-sugar meal using a within-subject design to test blood glucose and rsfMRI following: 1) an overnight fast and 2) a high-sugar breakfast (720 total kcals, 86g sugar) in 27 individuals (mean BMI 26.8). Independent component analysis resulted in 10 validated brain networks that were used to test within-network functional connectivity differences as a function of food intake. Fed vs. fasted resulted in an increase in blood glucose (p<0.0001) and modulation of sensorimotor networks. Specifically, intake of a high sugar breakfast increased connectivity within the oral somatosensory (gustatory processing, i.e., mouth feel) and dorsolateral prefrontal (dlPFC; contextual stimuli control) cortices (voxels=13; coordinates (mm)=-50,8,24; FWEp_corrected =0.03). This result suggests that increased connectivity between state-based behavior control (dlPFC) and somatosensory areas may be a neural signature of a post-prandial state.