This study examines how consumer expectations influence food consumption in all-you-can-eat restaurants. Conducted with 313 diners at a Korean BBQ buffet offering premium and standard menu options, participants were randomly assigned to one of four groups based on their menu choice and whether they received a surprise discount or a free upgrade. Results show that higher expectations—shaped by cues like price and perceived food quality—lead to increased consumption. Unexpected discounts or free upgrades did not significantly alter consumption, suggesting that once expectations are set, they strongly guide behavior regardless of actual changes in offerings. Nonetheless, both types of expectancy violations improved perceived satiety and value. These findings highlight that consumption behavior is anchored in initial expectations, which persist even when actual conditions change, emphasizing the psychological over the economic determinants of buffet dining behavior.
