Macro partitioning
Shifting US protein intake by reducing total volume by 25% and changing the animal-to-plant ratio from 85:15 to 60:40 aligns consumption with dietary recommendations while significantly reducing environmental impact.
To improve both your health alignment and environmental impact, reduce your total daily protein intake by about a quarter and shift your sources. Instead of 85% of your protein coming from animal sources (meat, dairy, eggs), aim for 60% animal and 40% plant (beans, lentils, nuts, grains). This shift aligns with official dietary guidelines and significantly lowers your carbon and water footprint without compromising nutritional adequacy for the average adult.
A 25% decrease in protein intake paired with a 25% shift from animal food to plant food protein intake—from an 85:15 ratio to a 60:40 ratio—would best align protein intake with national dietary recommendations while simultaneously resulting in 40% fewer CO2eq emissions and 10% less consumptive water use.
Why this rating
Based on modeling using established national dietary guidelines, USDA/FAO data, and meta-analyses of environmental impacts, though it is a projection rather than a randomized controlled trial.
Source
Maximizing the intersection of human health and the health of the environment with regard to the amount and type of protein produced and consumed in the United States
Christopher D. Gardner et al. · Nutrition Reviews · 2018
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