Influence of eating together on brain activation and hedonic evaluation in response to foods.

Previous research has documented the influence of eating together on people's food expectations and choices. We conducted an fMRI study to investigate the influence of the label "eating together" on behavioral and brain responses to healthy or unhealthy foods. The participants (N = 28, 13 females; mean age = 21.19) viewed food photos presented with a label of "eating together" or "eating alone" and estimated the palatability, pleasantness, and desirability of each food. The label "eating together" elicited more positive ratings for both healthy and unhealthy foods than the label "eating alone," and this effect of social context was larger for unhealthy than healthy foods. The label "eating together" also elicited greater activation in the left insula and the right posterior insula for unhealthy foods (p = 0.001 and p = 0.004, whole-brain corrected, respectively). These findings suggest that a label of "eating together" can enhance the reward values of foods, with a potentially greater enhancement for unhealthy foods.