What are the best sources of protein? Introducing the BPI Score

Abstract

The question, “What are the best sources of protein?” is complicated by the significant hidden health and environmental costs associated with many popular options. Existing food rating systems, such as nutritional traffic lights and carbon footprint labels, are valuable but often unidimensional. This narrow focus can conceal critical trade-offs and mislead consumers by failing to present a holistic picture. This perspective paper introduces the BPI Score, a new, multidimensional rating system designed to provide a more comprehensive answer. The goal is not necessarily to create another front-of-package label, but to foster a new literacy that empowers consumers, policymakers, and organizations to make more informed decisions. The initial version (V1) of the BPI Score was used to evaluate 20 high-protein products across two primary categories: people and planet. The Planet Score assesses environmental impact using data on GHG emissions, water pollution, and resource use. The People Score considers health factors like sodium and saturated fat content alongside accessibility metrics such as affordability and availability. A clear disparity emerged between plant-based and animal-based proteins. Tofu emerged as the highest-scoring product, while cheddar cheese ranked last. The top quintile of products consisted solely of plant-based proteins, while the bottom quintile was composed entirely of animal-based proteins. While acknowledging the limitations of this first iteration, the score provides a robust foundation for a more nuanced conversation. Ultimately, beyond the spreadsheets and scores, lies a fundamental reckoning: our protein choice is a referendum on the compassion we are willing to show to the planet and to future generations.