Undernutrition and the Dietary Transition What economics can learn from nutrition, and vice-versa

1. William A. Masters Friedman School of Nutrition & Department of Economics, Tufts University http://sites.tufts.edu/willmasters | http://sites.tufts.edu/foodecon (Some of) Undernutrition and the Dietary Transition What economics can learn from nutrition, and vice-versa UC Network on Child Health, Poverty, and Public Policy 6 September 2019

2. Undernutrition and the dietary transition vocabulary | nutrition | economics | conclusions (Some of) Undernutrition and the Dietary Transition What economics can learn from nutrition, and vice-versa • Vocabulary • Some of the many differences of language and professional practice that can limit collaboration and learning • Nutrition • Some facts about dietary intake and health outcomes that I’ve learned, after a decade of teaching in a nutrition school • Economics • Some facts about farm production and food markets that I’ve learned, from 30 years of research in agricultural economics • Conclusions

3. Undernutrition and the dietary transition vocabulary | nutrition | economics | conclusions Economists and nutritionists use similar data and similar words, but mean very different things For example, what is “a grant”? What is “data”? And what is “a model”? In clinical nutrition, a model might look like this: In public-health nutrition, a model might look like this: A causal pathways diagram (left to right, over time) The UNICEF framework (underlying vs proximate causes) A social-ecological model (scale of observation)

4. Undernutrition and the dietary transition vocabulary | nutrition | economics | conclusions Economists and nutritionists use similar data and similar words, but mean very different things For economists, “models” are one or more equations, like these: In nutrition, these would probably be called “mechanisms”, e.g. the Krebs cycle in nutritional biochemistry An individual household (here, a “net seller” of nutritious food) A community of farm households (here, they “export” nutritious food) Price of nutritious foods (pesos/kg) Qty. of the farm household’s other goods (kg/yr) Nutrition: Diets & behavior Agriculture: natural resources and technology Consumption Supply curve Indifference curve Production Price in trade Production Consumption Markets & policy: Interactions between people Agriculture: natural resources and technology Markets & policy: Interactions between people Demand curve Production possibilities frontier Nutrition: Diets & behavior Price in trade Qty. of farm household’s nutritious foods (kg/yr) Qty. of the region’s nutritious foods (tons/yr)

5. Undernutrition and the dietary transition vocabulary | nutrition | economics | conclusions There are big differences between nutrition & economics in professional practices at all stages of research Some big differences include: replication & meta-analysis statistical methods project selection & planning authorship & citation standards of evidence pay & working conditions dissemination uptake of results Data analysis Journal publications Research design Data collection Abstracts & presentations Societal impact Project funding Scientific impact • gov’t. agencies • nonprofit orgs. • companies • individuals • results • hyp. tests • variables • abstracts • posters & slides • working papers • citations • data • methods & code • motivation • methods • size & scope • personnel • budgets • activities • new observations • proprietary data • public data • gated (subscriber pays) • open access (author pays) • sponsored (funder pays) Practices may be driven by outside influences: Funders Scientific community (media & social) Decision-makers in organizations Collaborators Data sources Editors & referees Examples of ways that nutrition differs from economics: Many co-authors, first & last author gets most credit; Results often embargoed in pursuit of press coverage Opening paragraph is about the disease, not the project Most work is grant-funded, and work is often delegated to post-docs Most work follows a stylized protocol, e.g. CONSORT and PRISMA Primary concern is conflicts of interest (e.g. nutrition.org/ensuringtrust) Also, increasing focus on transparency and replication, although still less sharing of data and code than in economics Also, more and shorter papers, with more citations (+ role of pubmed) …then methods are spelled out in detail; little focus on novelty Nutritionists can use NutriXiv.org Economists are also preregistering, e.g. aspredicted.org

6. Undernutrition and the dietary transition vocabulary | nutrition | economics | conclusions Nutrition and economics have long been interconnected “The rich man consumes no more food than his poor neighbour. In quality it may be very different, and to select and prepare it may require more labour and art; but in quantity it is very nearly the same.” -- Adam Smith (1776), “On the rent of land”, chapter 11 in Wealth of Nations This is true only in the short run The dietary transition towards more and better food, 1961-2013 Nutrient-rich foods (not cereal grains or starchy roots, as a percent of energy) Dietary transition towards more food per day, bigger people (and more waste?) as well as shift to fancier foods Undernutrition remains widespread in some places Total dietary energy (calories/capita/year) Data shown are from FAO Food Balance Sheets, http://www.fao.org/faostat/en/#data/FBS. Europe includes all of the former Soviet Union.

7. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions What Adam Smith got right, and what we’ve learned since then • Metabolic set points make dietary intake roughly isocaloric (me ≈ 2584 kcal/day) • deviations drive change in weight (for me, approx. 24 sodas = 1 lb) or level of physical activity (for me, approx. 16 min. run ≈ 1 soda) also change with body composition & disease (age, height, gut health) • Improved diets + sanitation leads to taller, bigger people • stunting below potential height mostly occurs before age 2, rarely reversed • weight gain through fat deposition occurs gradually, very difficult to reverse • As other risks decline, diets have become world’s #1 health risk factor • persistence of undernutrition and nutrient deficiencies, especially in early life • dietary transition drives obesity, cardiometabolic & other risks in later life • key health attributes are invisible, discovered gradually by nutrition science • new foods with limited history are especially prone to information failures Hall et al 2011 (www.niddk.nih.gov/bwp); IOM 2006; Tooze et al. 2007; Shetty 2005; MyPlate 2018

8. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions What have nutritionists discovered? • Nutritional discoveries trace the history of science • limes prevent scurvy (J. Lind in Britain, 1747) • food contains energy (A. Lavoisier in France, 1770) • boiling & sealing preserves food (N. Appert in France, 1810) • energy can be protein, fats or carbs (J. Liebig in Germany, 1840) • germ theory & pasteurization of milk (L. Pasteur in France, 1864) • “vitamines” must exist, because rice husks prevent beriberi (1912) • vitamin C is first to be isolated, shown to prevent scurvy (1936) • Nutritional discoveries have driven government intervention • nutrient adequacy was focus of first dietary guidelines (1941) • nutrient fact panels introduced (1993 for packaged foods, 2018 for menus) • epidemiological data demonstrates additional role of food groups (1990s) • fruits & vegetables first separated out in U.S. dietary guidelines (2000) Mozaffarian, Rosenberg and Uauy 2018

9. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions In a very poor country (Malawi), what undernutrition is most severe? Data on individuals’ intake is very scarce and expensive, so we use household data instead • We add up all household members’ requirements for a healthy & active life in terms of 21 essential nutrients, which vary by age, sex, pregnancy and breastfeeding • We assume that individuals share the family diet in proportion to energy needs, maintaining energy balance • The most severe deficits in this context are for zinc, riboflavin, selenium and vitamin B12 • These nutrients have a variety of functions, and are often supplied by animal-sourced foods • Some gaps can be filled through fortification, but currently only for Vitamin A (in sugar & cooking oil) The most under-consumed nutrients include total fats, some vitamins and minerals Source: CANDASA project results, from Schneider et al. (2019)

10. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions The cost of nutrient adequacy varies but often above poverty lines Using prices for 55 items at 29 markets in all regions of Malawi every month for 2007-2017, their composition in 21 nutrients from the new Food Composition Table (FCT) for Malawi, plus upper & lower bounds for health in 35 Dietary Reference Intake (DRI) constraints, we find: Expense is highest in pregnancy and lactation; Well above local and global poverty lines Cost per day (US$ at 2011 PPP prices) Cost per 1,000 kcal (US$ at 2011 PPP prices) A more expensive mix of foods is needed for children, adolescent girls, women and the elderly $1.90 $1.50 Source: CANDASA project results from Y. Bai et al. (2019)

11. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions The Malthusian threat of rural population growth has shifted to Africa Number of people (billions) Africa’s rising rural population keeps workers in agriculture, and keeps children in poverty, until farming conditions improve After each turning point, those remaining in rural areas can expand land use per farm household (The U.S. peak was around 1914, after which falling rural populations and rising farm sizes continued until 1990s) Data shown are author’s calculations from UN World Urbanization Prospects, 2014 Revision, from http://esa.un.org/unpd/wup.

12. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Remember this? In Africa, the dietary transition is just beginning The dietary transition towards more and better food, 1961-2013 Nutrient-rich foods (not cereal grains or starchy roots, as a percent of energy) Total dietary energy (calories/capita/year) Data shown are from FAO Food Balance Sheets, http://www.fao.org/faostat/en/#data/FBS. Europe includes all of the former Soviet Union.

13. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Overcoming malnutrition involves many drivers of change • Income growth and safety nets,in cash or in kind • Relative prices and convenience,for healthier vs. less healthy items • Knowledge, norms and beliefs, among all options at home and away • Standards and regulation,to address information failures For example: • Britain creates Assize of Bread and Ale for quality & weight (1266) • U.S. creates the FDA & has USDA inspect meat (from 1906) • Supreme Court rules against false advertising (vinegar, in 1924) • FDA sets first packaged food standard (canned tomatoes, in 1939) • FDA defines and regulates additives, creates GRAS list (in 1958) • Organic standards introduced (in 1990) • trans fats found harmful, mandatory disclosure (2006) then removal (2015) Ross 1956; FDA 2018

14. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions What role does agriculture play in nutrition and the dietary transition? Almost all farms (>95%) remain family enterprises, even in rich countries Agriculture-nutrition linkages are asymmetric but input supply and the food industry have scale economies, employees and equity investors Input supply Farms & agribusinesses provide food commodities, so can help end undernutrition through higher farm income and lower food prices Most of the world’s undernutrition occurs in farm families Farms With access to markets, food consumption becomes separable from food production Food companies transform commodities and other inputs into products, like any manufacturing sector Food industry Food consumers

15. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Africa’s fast rural population growth keeps most of its workers on farms Share of all workers in each country working in agricuture (percent) 1991 (green circles) 2010 (blue squares) At each level of national income, agriculture employs a larger share of workers in Africa than in other regions African countries All other countries …and at each income level, there was no shift from 1990s to 2010s These are “Preston curves”, showing national averages at each level of per-capita income Source: Reprinted from W.A. Masters, N.Z. Rosenblum and R.G. Alemu, 2018. Agricultural transformation, nutrition transition and food policy in Africa. Journal of Development Studies, 54(5): 788-802. Employment data are ILO (2015), national income is from World Bank (2018).

16. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions African children are more likely to be stunted, but big gains over time Share of all children in each country who are stunted, WHZ<-2 (percent) 1990s (green circles) 2010s (blue squares) At each level of national income, stunting rates are higher in Africa than in other regions African countries …but that fraction has shifted down, due to innovation in child health All other countries Source: Reprinted from W.A. Masters, N.Z. Rosenblum and R.G. Alemu, 2018. Agricultural transformation, nutrition transition and food policy in Africa. Journal of Development Studies, 54(5): 788-802. Stunting are World Bank, WHO and UNICEF joint data, national income is from World Bank (2018).

17. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions In Africa, there is more obesity in higher-income countries Share of all adults aged 20+ in each country, BMI>30 (percent) All other countries African countries In Africa, there is a strong income gradient and little upward shift in obesity prevalence at each income level, at least by 2010 From 1990 to 2010, there was a shift up at each income level in richer countries 2010 (blue squares) 1990 (green circles) Source: Reprinted from W.A. Masters, N.Z. Rosenblum and R.G. Alemu, 2018. Agricultural transformation, nutrition transition and food policy in Africa. Journal of Development Studies, 54(5): 788-802. Obesity is from Global Burden of Disease study, national income is from World Bank (2018).

18. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions The dietary transition involves rising levels of packaged food sales Packaged food sales (kcal/person/day) by level of national income, 2009-2016 Food systems differ: packaged food sales don’t always rise with national income GNI per capita, PPP (constant 2011 US dollars), log scale Source: Packaged food sales are estimated by Euromonitor, and are available for the 54 countries shown. National income is GNI per capita in constant US dollars at 2011 PPP prices. Darker dots show later years.

19. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Relative prices for food are lower at higher levels of national income Average price level for household expenditure in national accounts, 2011 High cost in poor countries could be due to low productivity of local food systems, and international competition for traded goods GNI per capita, PPP (constant 2011 US dollars), log scale Source: Author’s calculations, from World Bank, International Comparison Program (ICP) data for the CANDASA project (http://sites.tufts/edu/candasa). Note: Data shown are average prices for goods & services in selected sectors, relative to that sector’s price level in the U.S., at each level of national income per capita measured at purchasing power parity prices in 2011, estimated by local polynomial regression for 159 countries.

20. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Price indexes for the cost of nutritious foods reveal food system change The CANDASA project uses price data to calculate alternatives to the CPI based on nutritional value • Cost of Nutrient Adequacy (CoNA) • From Dietary Reference Intakes for 21 macro- and micro-nutrients -- Use a total of 35 upper and lower limits for intake (e.g. mcg/day) • Select least-cost foods to provide nutrients in required proportions -- Results use 6-8 items at each place and time to meet all constraints • Cost of Recommended Diets (CoRD) • From Dietary Guidelines for quantity consumed from each food group -- Use target quantities of foods in each group (e.g. servings/day) • Select least-cost foods from each group in required proportions -- Results use 6-8 items, with more expensive foods than CoNA • Nutritionally-weighted Consumer Price Index (nCPI) • Use Nutrient Profile scores for each food’s contribution to health • Count all foods in the CPI basket, with nutritional weights

21. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Food price trends differ greatly by food group Using prices for 92 items at 120 markets in all regions of Ethiopia, monthly from 2001 to 2017 Seasonal patterns and trends differ by food group Rising prices for nutrient-rich foods Falling prices for green revolution crops Source: CANDASA project results from F. Bachewe et al. (2019)

22. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Overall diet costs have complex patterns of seasonality Using prices for 64 items at 21 markets in all regions of Tanzania, monthly from 2011 to 2015, with nutrient composition and all Dietary Reference Intake (DRI) constraints for a representative adult woman Seasonality in diet cost varies by region Seasonality varies by type of food Starchy staples Width shows estimated period of higher prices Dark dots show statistically significant peaks Colors show magnitude of seasonal rise Pulses Animal foods (and processed foods) have the least seasonality Animal foods Fruits and veg. Fruits and vegetables have the most seasonality, and also variation in peak timing Source: CANDASA project results from Y. Bai et al. (2019)

23. Undernutrition and the dietary transition vocabulary| nutrition | economics | conclusions Conclusions: international nutrition can inform US policy • Agriculture drives end to undernutrition, but the food industry drives dietary transition • In poor rural areas, low farm incomes and high food prices are linked to persistent undernutrition • With economic development, shift to packaged foods involves information failure • Food is increasingly regulated like other manufacturing sectors (e.g. vehicle safety, fire codes etc.) • Poverty-related deficits in early childhood are followed by excesses in later life • Public services for pregnancy and infancy, then information and regulation for adult nutrition • Many foods and nutrients have U-shaped risk curves, calling for Goldilocks nutrition => Food markets and food policies are very sensitive to nutrition research findings • Nutritionists and economists have much more to learn from each other • Barriers to collaboration remain high, due to big differences of language and professional practices • The two domains are highly complementary, but paradigm shifts are required • For economists, recognizing that food is a manufacturing sector with information failures • For nutritionists, recognizing that diets depend on consumer choice and market equilibrium => Many opportunities for work ahead!