Rising adoption and retention of meat-free diets in online recipe data

The current and growing demand for animal protein exerts immense pressure on the environment through diverse effects such as land-use change, water use and greenhouse gas emissions. Curbing meat demand by transitioning to largely plant-based diets is key to increasing food system sustainability. In this study, we investigate dietary transitions by analysing a dataset of over 240,000 recipes with 2.5 million user ratings from the most popular German recipe website. We find an increase in the vegetarian and vegan recipes submitted, with annual growth rates of 16% and 3.5%, respectively. We further detect a consistent relative increase in the number of users switching to these diets and maintaining them over the last 8 years. We show that the transition is eased by initially switching to vegetarian diets that resemble meat-based ones in their ingredient makeup. These findings are corroborated by qualitative interviews with users who have recently switched diets. Our results demonstrate the application of recipe metadata to determine individuals' dietary choices and large-scale food trends, and identify pathways to a more sustainable food system.