This study investigates the role of dietary lifestyles and household dynamics in shaping European adults' plant-based food purchase intentions. We first obtained cross-cultural data encompassing 6067 participants, balanced for age and gender from ten European countries. We then classified the respondents based on their self-reported dietary lifestyles (omnivores and non-omnivores). We also grouped the participants based on the dietary lifestyles of the members of their households, whether the respondents were living with omnivores or non-omnivores. We then asked the participants to what extent they would like to purchase plant-based food in the future, from a list of various plant-based food types. To determine pertinent associations between dietary lifestyles and household type, we utilized chi-square association tests. Afterwards, we identified any significant differences across respondent groups in terms of plant-based food purchase intentions through the ANOVA procedure. Our findings revealed that in heterogenous households (households with different dietary lifestyles), the presence of a non-omnivore individual in the household was associated with higher plant-based food purchase intentions of the omnivore respondents. Further, the number of individuals with alternative diets in the household did not have any additive effect towards consumers' purchase intention. Our study thus underscores the role of household composition on shaping dietary choices and highlights the potential for households with non-omnivores to drive shifts towards plant-based food consumption. Finally, this study suggests that focusing on the relationships among heterogeneous households (and not only on the number of cohabitants with varying dietary lifestyles) can promote plant-based consumption and meat reduction behaviors.