Acute diet soda consumption alters brain responses to food cues in humans: A randomized, controlled, cross-over pilot study

Background: Diet soda consumption has frequently been linked to obesity and its comorbidities in epidemiological studies. Whether this link is causal and a potential mechanism remains to be determined. Aim/Methods: This randomized, cross-over, controlled pilot study sought to determine whether there may be changes in reward-related brain activations to visual food cues after acute consumption of diet soda versus regular soda or carbonated water using functional magnetic resonance imaging. Results: Diet soda as compared to carbonated water consumption increased activation of reward-related caudate to highly versus less desirable food cues. Diet soda as compared to regular soda increased reward-related insula and decreased activation of cognitive control-related dorsolateral prefrontal cortex to food cues versus non-food cues. No changes in ratings of hunger an hour after beverage consumption were observed. Conclusions: These results may suggest a potential mechanism for diet soda to increase food palatability through activation of the reward system and suppression of inhibitory control that remains to be confirmed by future studies.