The Environmental Costs of Building Human Muscle

Among the general population, it has been established that plant-based diets confer significant environmental benefits (greenhouse gas emissions, land use, and water use) compared to omnivorous diets. However, sports nutrition recommendations for supporting resistance exercise-induced gains in muscle mass and strength differ substantially from population-level recommendations, especially for protein intake. Therefore the difference in environmental impact between omnivorous and plant-based diets for adults following such recommendations is as yet unknown. A prior analysis found that a high-protein, non-animal-derived diet can support resistance training-induced gains in muscle mass and strength to the same extent as a protein-matched omnivorous diet. These findings align with previous research showing that, in the context of a high-protein diet, the source of protein - whether animal or plant-based - does not affect the rate of resistance exercise-induced gains in muscle mass and strength. The present study therefore plans to retrospectively analyze the diet records from previously published research to determine the difference in environmental impact between the high protein animal-free and omnivorous diets. The findings could highlight the unique difference in environmental impacts between those following high protein plant-based and omnivorous diets.