Vegan diets eliminate direct consumption of animal products and are often motivated by animal welfare concerns. Understanding the evidence for their welfare impact helps assess their effectiveness.
The welfare case for plant-based diets is quantitatively strong: each person reducing or eliminating animal product consumption reduces demand for the intensive farming systems that cause significant welfare harm. Animal Charity Evaluators estimate over 100 vertebrate animals spared per year per person eating plant-based, with substantially higher numbers if invertebrate welfare is considered. The welfare argument does not require perfection — any reduction in animal product consumption in the direction of plant-based eating reduces welfare harm proportionally. The honest welfare assessment also acknowledges limitations: some plant agriculture involves pest control and habitat displacement that cause wildlife welfare costs, though these are generally much smaller than the welfare costs of equivalent animal agriculture.