The effect of spatial position of calorie information on choice, consumption and attention

We report a "lab-in-the-field" experiment designed to test the impact of posting calories on menus. The study adds substantially to previous work by testing different spatial arrangements of price and calorie information. Choices were real, not hypothetical, and participants were unaware that their lunch choice was part of a study, even though their eye-movements were being tracked. Participants exposed to calorie information ordered 93 fewer calories (11%) relative to a control group. The impact was strongest when calorie information was presented on menus just to the right of the price, in an equivalent font. The difference in number of calories consumed was greater still. These effects were mediated by knowledge of the amount of calories in the meal, implying that calorie posting led to more informed decision making. There was no impact on enjoyment of the meal. Eye-tracking data suggested that this arrangement altered the decision process such that greater decision weight was given to calorie content.