Sustainability Of Meat-Based And Plant-Based Diets

Worldwide, an estimated 2 billion people live primarily on a meat-based diet, while an estimated 4 billion live primarily on a plant-based diet. The US food production system uses about 50% of the total US land area, 80% of the fresh water, and 17% of the fossil energy used in the country… The meat-based food system requires more energy, land, and water resources than the lactoovovegetarian diet. In this limited sense, the lactoovovegetarian diet is more sustainable than the average American meat-based diet. [Abstract excerpted from article]

World Health Organization (WHO) statistics estimate that more than 3 billion people worldwide are malnourished. The problem is primarily related to rapid world population growth and the declining availability of land, water, and energy resources. The U.S. population also continues to grow, doubling over the previous 60 years and projected to double again over the next 70 years. The U.S. food system accounts for 50% of total U.S. land, 80% of fresh water, and 17% of fossil energy used in the country.

This analysis compared lacto-ovo-vegetarian and meat-based diets. The amount of feed grains used to produce the milk and eggs consumed by lacto-ovo-vegetarians was about half the amount used to feed the livestock needed to produce the animal products consumed in the meat-based diet.

The U.S. livestock population consumes more than 7 times as much grain as that directly consumed by the American population. On average, Americans consume twice the recommended daily allowance for protein, though the amount is significantly lower for lacto-ovo-vegetarians. Producing 1 kg of animal protein requires about 100 times more water than producing 1 kg of grain protein. Livestock uses only 1.3% of total water used in agriculture, but if the water required for feed grain production is included, the amount increases dramatically.

This research concludes that “both the meat-based average American diet and the lacto-ovo-vegetarian diet require significant quantities of nonrenewable fossil energy to produce. Thus, both food systems are not sustainable in the long term based on heavy fossil energy requirements. However, the meat-based diet requires more energy, land, and water resources than the lacto-ovo-vegetarian diet. In this limited sense, the lacto-ovo-vegetarian diet is more sustainable than the average American meat-based diet.”