In-Depth Notes on Sustainability of Diets and Environmental Impact

Overview of Diets and Sustainability

• Global Diet Distribution:
  • Meat-based Diets: ~2 billion people
  • Plant-based Diets: ~4 billion people
• US Food System Consumption:
  • Land: 50% of total area
  • Fresh Water: 80%
  • Fossil Energy: 17%
• Sustainability Concerns:
  • Both diets not sustainable due to heavy reliance on fossil energy.

Comparison of Diets

Lactoovovegetarian Diet

• Basic Nutritional Needs: Can meet basic nutritional needs as per American Heart Association.
• Food Consumption Data:
  • Total Weight: 1002 kg/year (vs 995 kg for meat diet)
  • Major Caloric Sources: Food grains and sugar/sweeteners.
  • Cropland Usage: 0.4 ha (less than meat-based diet).
• Energy Efficiency:
  • Grains and legumes require less energy input than vegetables and animal products.
• Caloric Content Comparison:
  • Energy from food grains:
  • Lactoovovegetarian: 1132 kcal
  • Meat-based: 849 kcal

Meat-based Diet

• Meat and Fish Consumption:
  • Average: 124 kg meat, 20.3 kg fish/year
  • Caloric Content: 480 kcal from meat and fish.
• Livestock Impact:
  • US has >9 billion livestock, outnumbering human population by 5:1.
  • Livestock consumes 7 times the grains compared to human consumption, indicating substantial land and resource use.

Resource Use and Efficiency

Energy Inputs in Production System

• Average fossil energy input: 25 kcal fossil energy per 1 kcal of animal protein produced.
• Grain Production: Approximately 2.2 kcal of fossil energy for 1 kcal of plant protein.
• Livestock Efficiency Ratios:
  • Broilers: 4:1
  • Turkeys: 10:1
  • Milk: 14:1
  • Pork: 14:1
  • Beef: 40:1
  • Lamb: 57:1

Land Resources

• Land Used for Food Production: >99.2% of food in the US produced on land.
• Soil Erosion Issues:
  • Estimated annual loss: 10-13 times the sustainable rate.
  • Approximately 500 years to replace 1 inch of lost soil.

Water Resources

• Fresh Water Use:
  • Agriculture: Major consumer (85% irrigation).
  • Water Needed for Crop Production: 500-2000 L/kg of crop.
  • Beef Production Spatial Comparison:
  • 100 kg of beef may require 100,000 L of water.

Conclusion

• Both diets require significant quantities of non-renewable fossil energy and are unsustainable.
• Lactoovovegetarian diet = More sustainable than meat-based diet in terms of resource requirements.
• Rapid population growth: A crucial factor leading to increased strain on limited natural resources.