Asymmetric behavioural responses to updating caloric information

Calorie labels are widely used as an information disclosure policy, yet their behavioural effects remain debated. Across four studies ( N = 2,067), including one nationally representative online sample of the U.S., we examine how individuals adjust portion-size choices after updating misperceptions about meal calorie content. Using more than 45,000 incentivised calorie estimates and 6,000 food choices, we find that food characteristics, not individual traits, better predict misperceptions, and that larger misestimations are associated with extreme portion choices. Portion-size adjustments after a label reveals the caloric content are substantially smaller than the initial estimation errors. Responses are asymmetric: correcting underestimation is associated with larger reductions in portion size than the increases observed after correcting overestimation. Individuals who estimate calories accurately show little to no adjustment. Increases after correcting overestimation are concentrated among healthier foods and lower-conflict eaters. These results highlight asymmetric behavioural responses to disclosed information and suggest that average calorie changes may obscure important heterogeneity.