Plant-based diets benefit individual health and the environment, yet most people eat omnivorous diets. We aim to (1) assess the role of multiple determinants for transitioning to more plant-based diets in a sample of omnivorous respondents, such as recommendations from doctors, scientists and politicians; lower costs; and increased availability, and to (2) identify which subpopulations are most receptive to which determinants. Using data from a survey on the use and acceptance of Traditional, Complementary and Integrative Medicine in Germany (N = 4065; N omnivorous = 3419; 84%), we find that the overall willingness to change to a more plant-based diet is low (mean = 2.25 on a scale of 1–4). Respondents are most willing based on doctors' recommendations (mean = 2.61), and if prices for plant-based products were lower (mean = 2.55), and least willing based on scientists' and politicians’ recommendations (mean = 1.86). Regression analyses reveal that men, the baby boomer cohort, and respondents with lower levels of education have a significantly lower willingness to transition to more plant-based diets. Further, recommendations from doctors, scientists, and politicians appear to be promising interventions for addressing the dietary behavior of men and older cohorts. Interventions by doctors and lower prices for plant-based products have the highest potential to induce dietary change even among the reluctant, reducing health inequalities and promoting environmentally friendly behavior.