5.9

Chapter 9: Food and Hunger

Overview of Global Food Production

• Food supplies have kept pace with human population growth over two centuries.

  • Population growth: 1.08% per year.

  • Food production growth: 2.2% per year.

Chronic Hunger and Food Security

• Food Security: The ability to obtain sufficient food daily.

• Poverty: The greatest threat to food security.

• Changes in dietary energy and protein consumption observed in selected regions.

Global Hunger Statistics

• Hunger distribution illustrated by population percentages:

  • 35%: Critical hunger zones.

  • 20 to 35%: Moderate hunger.

  • 5 to 20%: Mild hunger.

  • < 5%: Relatively food-secure regions.

Causes of Famines

• Famines: Large-scale food shortages leading to massive starvation and social disruption.

  • Immediate triggers: Environmental conditions.

  • Underlying causes: Political oppression, armed conflict, economic chaos, and hoarding.

  • Mass migrations often result when productive capacity is lost.

Rising Overeating Issues

• In developed countries, processed foods high in sugar and fat dominate diets.

  • Statistics: 64% of Americans are overweight; 33% are obese (BMI > 30 kg/m²).

  • Health impacts include hypertension, diabetes, heart disease, and certain cancers.

  • Emphasis on the need for dietary and lifestyle changes.

Nutritional Guidelines

• Harvard Food MyPlate Pyramid (2011):

  • Recommended sparingly: Red meat, processed meats, butter, refined grains, and sugary drinks.

  • Essential food groups include dairy, fruits, vegetables, and whole grains.

  • Encourages daily exercise and weight control.

Vitamin Deficiencies and Their Consequences

• Malnourishment: Occurs from dietary imbalances or inability to absorb nutrients.

  • Affects 3 billion people worldwide, leading to serious health issues including illnesses and fatalities.

Major Nutrients in Human Foods

• Carbohydrates: Main energy source (4 Cal/g), found in sugars, wheat, and rice.

• Lipids: Support cellular membranes (9 Cal/g), derived from fats and oils.

• Proteins: Build and maintain body structures (4 Cal/g), sourced from both animal and plant products.

Common Nutritional Problems

• Iron Deficiency: Most prevalent imbalance, leads to anemia, increased mortality in childbirth.

• Iodine Deficiency: Causes goiter, stunted growth, lower mental capacities.

• Vitamin A Deficiency: Affects 140 million children globally, leading to blindness in 350,000 annually.

Protein Deficiency Diseases

• Kwashiorkor: Results from a lack of high-quality protein; symptoms include discolored skin and bloating.

• Marasmus: Caused by inadequate calorie protein intake, characterized by extreme thinness and low immunity.

Key Food Sources

• The majority of global nutrient needs are met through three crops: corn, wheat, and rice, with about 2 billion metric tons grown annually.

• Additional staples include:

  • Cool climates: Potatoes, barley, oats, rye.

  • Warm climates: Cassava, sweet potatoes, roots, tubers.

Global Grain Production (2018/19)

• Corn: 1,099.61 million metric tons.

• Wheat: 734.74 million metric tons.

• Rice (milled): 495.87 million metric tons.

• Other grains include barley, sorghum, oats, and rye.

Meat Consumption Trends

• Increased meat consumption: rising from 10 kg/person/year in developed countries (1960) to 26 kg/person/year; in the US, from 90 kg/person/year to 136 kg/person/year.

• Meat as a concentrated protein source, but its production is costly (8 kg of grain for 1 kg of beef).

Intensive Meat Production Practices

• Confined Animal Feeding Operations (CAFO): Animals raised in enclosures to ensure rapid growth using a grain-based diet.

• New livestock breeds developed for higher productivity and disease control.

Environmental Impact of Meat Production

• Producing kg of meat is significantly more energy-intensive than producing plant-based foods.

• Livestock accounts for 20% of global greenhouse gas emissions.

• Reducing meat consumption can lead to substantial environmental benefits.

Seafood as a Protein Source

• Seafood supports 1.5 billion people in developing nations.

• Fisheries globally are declining, risking commercial sustainability.

  • Concerns of extinction of fisheries by 2050 if current practices continue.

  • By-catch from fishing causes species depletion.

Aquaculture

• Aquaculture: Increasing share of seafood production but has environmental downsides.

  • Uses wild stock to farm species, potentially damaging ecosystems.

  • Raises concerns over disease spread and pollution.

Risks of Intensive Food Production

• Land conversion for animal feed increases soil erosion.

• Antibiotic use in agriculture contributes to resistant pathogens.

• Intensive processes lead to higher fossil fuel use.

Green Revolution and Its Impact

• Introduced technological advancements in crop production.

  • Significant increase in yields; e.g. corn yields from 25 to 160 bushels/acre.

• Initiated over 50 years ago, assisting developing nations.

Genetic Engineering in Agriculture

• Genetic engineering creates GMOs with new traits for better resilience.

  • Benefits include pest resistance and nutrient enhancement.

  • Applications include vaccines in food products.

Concerns About GMOs

• Potential for creating superweeds and reducing biodiversity.

  • Disparity in technology access could marginalize poor farmers.

  • GMOs already prevalent in the US food supply (≈60% processed food).

Transgenic Crops

• Engineered to withstand high pesticide levels (e.g.