Reducing food waste through consumer behavior modification is crucial, yet collecting representative and primary data for key consumer segments and identifying the primary influential factors remain challenging. In this study, we utilized structural equation modeling (SEM) and large-scale direct weighing-based food waste data to examine the influence mechanisms of plate waste behaviors in urban restaurants in China. Our findings revealed that the number of consumers sharing a table and income level were the most significant factors directly contributing to plate waste. Conversely, the frequency of taking leftovers home and frugality concerns directly reduced plate waste, especially in large restaurants or when dining with families. Notably, income level showed opposing effects on behavior in fast-food restaurants and large restaurants. These results offered valuable insights into effective policies for nudging consumer behavior change and reducing food waste in restaurants.