• Are visual cues or internal cues better at controlling consumption?
• The hypothesis: people's ability to estimate actual amount of food will be impaired if they are deprived of visual cues by eating in the dark. People's satiety after the meal in the dark is less contingent on actual amount of food they previously ate, compared to eating in the light.

Study Design

• Double-blind experiment: neither the participants nor the servers knew which portion size they were receiving/giving.
• Split into groups: Group 1 : Two days of groups of 32 in the dark. Half receive regular portions and half receive super sized Group 2 : One day of 32 in the light. Half receive regular and half receive super sized *Dessert is in the light for all of them

Conclusion

The author of Diner Beware present only half of the findings: while people who ate super-sized portions in the dark indeed ate just as much dessert as those who ate regular-sized portions, this was not the case for people who ate in the light. Those people who ate super-sized portions in the light did end up eating less dessert than those who ate the regular-sized portions, suggesting that they were able to judge satiety.