Changing dietary habits towards a reduction of animal origin proteins, such as meat and fish, in favor of plant-based alternatives can positively contribute to sustainability, health and animal suffering related issues. Despite this awareness and the large variety of plant-based alternatives available on the market, willingness to reduce or substitute animal origin proteins is still very low. This research investigates the role of a so far overlooked factor in the study of consumer adoption of plant-based diets, namely the role of food processing, adding to the understanding of how consumers perceive animal origin products and their plant-based alternatives imitating a minimally processed vs ultra-processed food. Through a Swiss online study with 607 consumers, our results showed that the resemblance to a minimally processed (e.g., chicken filet, tuna) or ultra-processed product (e.g., meatball, fish stick) differently affect animal origin products and plant-based imitations. Specifically, while consumers perceived more positively the minimally processed meat/fish than the ultra-processed one in the animal origin category, in terms of perceived environmental friendliness, perceived health and purchase intention, the reverse was observed for the plant-based imitations. Thus, contributing to theory and practice, the results of this research suggest that the like-to-like imitation of an animal origin product is not only ineffective but can also be counterproductive for perceptions-of sustainability and health- and purchase intentions of plant-based alternatives.@en