The online-to-offline (O2O) food delivery market is booming worldwide in recent years. Yet, what factors influence diners' O2O food ordering behaviors are still not well understood. Adopting the elaboration likelihood model, this study examined how restaurant-generated information cues in O2O mobile apps impacts diners' expectations. The results from three experimental studies found that restaurant-generated information cues in mobile apps (i.e., message sidedness, information load, and image cues) influenced diners’ expectations differently depending on the levels of need for cognition. Findings of this study provide important implications for the restaurant industry to design marketing messages more effectively via O2O foodservice apps.