© T. M. Whitmore TODAY Nutrition Transition Theory: How does this all come together? Food Futures: Will there be enough food for the 21st century?  Reasons for concern  Issues around raising outputs

© T. M. Whitmore Related historic processes of change Interconnected “Transitions” Interconnected  Demographic Transition (DT) Demographic Transition  Stages of change in mortality and fertility => population growth over time  Regional differences-geography  Epidemiologic Transition (ET) Epidemiologic Transition  Shift in the patterns of causes of death over time  Regional differences-geography  Nutrition Transition Nutrition Transition  Shifts in dietary and physical activity- inactivity patterns  Regional differences-geography

© T. M. Whitmore The Nutrition Transition’s “Stage 1: “Collecting Food” Hunter gatherers  High in carbohydrates and fiber and low in fat, especially saturated fat  Activity patterns are very high with little obesity  Stages 1-2 of DTDT  First phase in ETET

© T. M. Whitmore The Nutrition Transition’s “Stage 2: “Famine”Famine Early agriculture and contemporary least developed areas generallyleast developed areas  Diet becomes much less varied and subject to larger variations and periods of acute scarcity of food  Little change in activity levels  Stages 1-2 of DTDT  First-Second phases in ETET

© T. M. Whitmore The Nutrition Transition’s “Stage 3: “Receding Famine”Stage 3 Scientific agriculture, early industrialization, and contemporary developing areasearly industrializationcontemporary developing areas  Consumption of fruits, vegetables, and animal protein increases, and starchy staples become less important in the diet  Activity patterns start to shift and inactivity and leisure becomes a part of the lives of more people  Stages 2-3 in DT  Second/Third Phases of ET

© T. M. Whitmore The Nutrition Transition’s “Stage 4: “Nutrition-related Non-communicable Disease (NR-NCD)”Stage 4 Associated with “modern” industrial lifestylesmodern” industrial lifestyles  A diet high in total fat, cholesterol, sugar, and other refined carbohydrates and low in polyunsaturated fatty acids and fiber diet high in total fat, cholesterol, sugar  Often accompanied by an increasingly sedentary life  Stage 4 in DT  Third Phase of ET

© T. M. Whitmore The Nutrition Transition’s “Stage 5: “Behavioral Change” “Post-modern” industrial lifestyles  A new dietary pattern => changes in diet associated with the desire to prevent or delay degenerative diseases and prolong healthnew dietary pattern  May be associated with increased “recreational” or health related exercise  Stage 4 in DT  Third Phase of ET

© T. M. Whitmore Food Futures reasons for concern I: Population Growth Population growth to 8-10 billion by 2050 (50% more than today!) All in less developed world (China = India each ~ 1.5 b)

© T. M. Whitmore Reasons for concern II: Dietary transitions Moving up on the food chain  Traditional diets => ~2400 kcal; 10% animal  Improved diets => ~3000 kcal; 25% animal Increased animal fraction => 4-5 times more animal feed (plant material) needs to be produced Overall need ~ 2x current harvest to get improved diet by 2050 for everyone

© T. M. Whitmore Reasons for concern III: Changes in agriculture Increases in pollution, erosion, and decreases in water availability potentially =>  Slow growth or even decrease Already slowing rates of growth of grain production per capita

© T. M. Whitmore Can we raise Output? 4 major areas of concern 1. Photosynthesis and crop productivity limits 2. Land, water, and nutrient (NPK) limits 3. Agroecosystems and biodiversity 4. Environmental change

© T. M. Whitmore 1) Photosynthesis & crop productivity limits There is an energetic limit:  Photosynthesis is < 5% efficient in converting sunlight to vegetative matter (even less if water or nutrients are short)  One way to address this is to improve the harvest index (= edible part/total biomass)  This is an area of possible progress  traditional wheat %  green revolution wheat %

© T. M. Whitmore 1) Photosynthesis & crop productivity limits There is an energetic limit:  Photosynthesis is < 5% efficient in converting sunlight to vegetative matter (even less if water or nutrients are short)  One way to address this is to improve the harvest index (= edible part/total biomass)  This is an area of possible progress  traditional wheat %  green revolution wheat %

© T. M. Whitmore 2) Land & soil limits I Agricultural land limits  ~ 1.5 giga (10 9 ) ha now cultivated and 1.6 giga ha (rainfed) potentially usable  Most area available for expansion in S.S. Africa & S. America savanna

© T. M. Whitmore 2) Land limits II Land needed per-capita  Traditional vegetarian diet =>  ha /capita  Chinese diet (2800 kcal; 15% animal)  ~ 1.1 ha/capita  Rich Western diet  ~ 4.0 ha/capita (much wasted and high meat fraction)  Better diet with some animal protein  ~ ha/capita  if 10 b people in 2050 =>  need 800 million ha to 3 gig ha (3000 million)

© T. M. Whitmore 2) Land limits III If 10 b people in 2050 =>  Need 800 million ha to 3 gig ha (now use 1.5 gig ha) Thus, no absolute limit due to amount of land if diet not excessive & all available land used – AND food can be moved from surplus areas to deficit areas Regionally per-capita land availability is more problematic for 2050  OK in Latin America  Adequate in Sub-Saharan Africa & Mid-East  Problematic in South & East Asia

© T. M. Whitmore 2) Water limits I Water: – in most systems water is the most important limit most years  Photosynthesis uses/needs lots of water also add evaporation and transpiration  mm water needed per ha for low- yielding crops  mm water needed by high yielding crops Current irrigation  ~ 250 million ha (only 8 m ha in 1800)  ~ 17% of all agriculture land  Creates 40% of all food

© T. M. Whitmore 2) Water limits II Current Water Use  Currently 5-7% of all available fresh water runoff used for agriculture  Even if water use only grew to match population =>  by 2050 agriculture will need 1/3 of all available fresh water

© T. M. Whitmore 2) Water limits III Crop and animal water use efficiency  Small grains and pulses =>  0.25 m 3 of water /million joules energy to humans (or about 1 liter per kcal)  Animals via grain and feed =>  25.4 m 3 water/m joules energy to humans (100x more!) or ~ 100 liters per kcal

© T. M. Whitmore 2) Water limits IV Water use in diets  Vegetarian diet (2500 kcal/day) =>  0.9m – 1.2 million liters/capita/year  Rich world diets (more kcal and more animal foods) =>  >> 2.0 m l/capita/year  Improved diets (more kcal and more animal foods than traditional vegetarian) =>  ~ 2 million l/capita/year  So – 10 b people =>  20,000 m 3 water or ~ 2/3 of ALL global runoff (assumes 2000 m 3 /capita/yr)

Demographic Transition Model Nutrition Patterns 1 & 2 Nutrition Patterns 3, 4, & 5

Nutrition Patterns 1 & 2 Nutrition Patterns 3, 4, & 5

New York Times

Stages of Health, Nutritional, and Demographic Change Focus on famine alleviation/prevention Focus on family planning, infectious disease control Chronic diseases predominate Reduced fertility, aging Focus on medical intervention, policy initiatives, behavioral change Focus on healthy aging spatial redistribution Demographic TransitionEpidemiologic TransitionNutrition Transition Receding pestilence, poor environmental conditions Reduced mortality, changing age structure High prevalence infectious disease Diet-related noncommmucable diseases predominate Receding famine High prevalence undernutrition High fertility/mortality Source: Popkin, Barry M. ( 2002) Public Health Nutrition 5:

Stages of the Nutrition Transition Urbanization, economic growth, technological changes for work, leisure, & food processing, mass media growth Pattern 3 Receding Famine Slow mortality decline increased fat, sugar, processed foods shift in technology of work and leisure Pattern 4 Degenerative Disease accelerated life expectancy, shift to increased DR-NCD, increased disability period reduced fat, increased fruit, veg,CHO,fiber replace sedentarianism with purposeful changes in recreation, other activity Pattern 5 Behavioral Change extended health aging, reduced DR-NCD MCH deficiencies, weaning disease, stunting starchy, low variety, low fat,high fiber labor-intensive work/leisure obesity emerges, bone density problems reduced body fatness, improved bone health Source: Popkin, Barry M. ( 2002) Public Health Nutrition 5:

Source: Source: USDA/Economic Research Service

Source: USDA/Center for Nutrition Policy and Promotion, March 3, 2006

Source: Source: USDA/Economic Research Service