In this article, we examine the effect on total calories chosen ofdisplaying an updated count of calories ordered in a sequential sandwich-building experiment, relative to a condition in which participantsreceive calorie information about each ingredient but would have tokeep track of the total number ordered themselves.The total number of calories ordered decreased significantly whenparticipants had access to an updating calorie counting tool.Participants in the calorie information and summation condition, CISum, ordered approximately 34 fewer calories than participants in thecondition in which they were simply provided information aboutcalories, CI. The incorporation of evidence on participants' estimates ofthe number of calories they ordered and differences in calories orderedsequentially between conditions shed light on how exposure to caloriesummation information influences individuals’ choices.