In the study, conducted by researchers David Just PhD., Ozge Sigirci, and Brian Wansink PhD. author of the forthcoming book, Slim by Design: Mindless Eating Solutions for Everyday Life, 139 diners in an Italian all-you-can-eat buffet restaurant were either charged $4 or $8 for the lunch buffet. The buffet offered pizza, salad, breadsticks, pasta, and soup. After finishing, diners were asked to rate the taste of the pizza and how much they enjoyed the dining experience on a 9 point scale.