The effect of ingredient-specific calorie information on calories ordered

Customers decrease calories ordered by 7.8% for build-your-own sandwiches when per-ingredient calorie information is introduced. There is no significant change in calories ordered for pre-defined sandwiches. Calorie reduction appears to result from substitution away from some higher calorie items, e.g., mayonnaise, towards lower calorie ingredients, like mustard. Despite low calorie content, customers did not increase the number of vegetables ordered. Finally, there is no attenuation of the effect of calorie information over time.