This research adopted the Theory of Planned Behavior (TPB) to predict intention and behavior to avoid food waste. In a pilot study, behavioral, normative, and control beliefs were identified. In the main study, a TPB model extended with descriptive and moral norms was assessed using a two-wave design and applying SEM. The associations between beliefs and TPB constructs were analyzed by MIMIC models. Attitude, descriptive and moral norms, and perceived behavioral control were associated with intention to avoid food waste, which predicted behavior. Considering the most important beliefs in forming intentions has important implications for designing food waste prevention interventions.