Objective: The current analysis used functional magnetic resonance imaging (fMRI) to explore a model of energy regulation postulating that the hippocampus integrates interoceptive signals and environmental stimuli to suppress responding to food cues. It was hypothesized that hippocampal activity would increase in response to food cues under postnutritive relative to fasted conditions, given the role of the hippocampus in integrating postnutritive signals with food cues, and that obesity, added sugar intake, or a combination of these factors would alter this response.
Methods: Data were analyzed on 65 participants (29 males). Participants consumed drinks containing 75 g of glucose or water and underwent an fMRI-based food-cue task. Blood-oxygen-level-dependent (BOLD) fMRI was used to examine hippocampal responses to food and nonfood cues.
Results: In lean participants, the hippocampal BOLD signal was higher following glucose compared with water, but participants with obesity showed the opposite pattern. BMI interacted with added sugar intake such that BMI was more negatively correlated with hippocampal food-cue reactivity after glucose ingestion in individuals who consumed high levels of added sugar. Hippocampal BOLD was negatively correlated with prospective food intake.
Conclusions: The findings are consistent with the view that energy regulation involves hippocampal processes in humans and that added sugar and excess weight may impair this function.
© 2021 The Obesity Society.