Reducing red meat intake is crucial for both planetary sustainability and human health. However, various psychosocial barriers impede this dietary shift, necessitating the application of psychological models such as the Theory of Planned behaviours (TPB) to predict individuals’ inclination to reduce red meat consumption. Despite TPB’s widespread use, there is a need for a more refined model addressing emotional variables. This study aims to assess TPB’s effectiveness in understanding intentions and behaviours regarding red meat reduction, while investigating food involvement’s role as a moderator between intention and behaviours. Data were collected through two questionnaires (n = 963, Time 1; n = 541, Time 2) filled out by a representative sample of the Italian population. Using descriptive statistics and structural equation models, findings reveal that attitudes and subjective norms explain 22.2 % of the variance in intentions to reduce red meat consumption. Additionally, perceived behavioural control and intention account for 39.7 % of the variance in self-reported meat consumption behaviours six months later. Moreover, high levels of food involvement hinder the translation of intention into behaviour, highlighting its moderating effect. These results emphasize the necessity of reshaping red meat reduction strategies and promoting alternative consumption choices, fostering habitual practices linked to positive emotions. It is crucial for reducing red meat consumption that this behaviour becomes a cultural symbol of change, identifying individuals as “new consumers” within a society adapting to environmental and health challenges. By integrating emotional factors into behavioural models, interventions can better address barriers and promote sustainable dietary habits.