Population Growth and Malnutrition
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Chapter 1.2 Population Growth and Malnutrition 31 Michael J Klag Parul Christian Dean, Johns Hopkins Senior Program Officer, Bloomberg School of Public Women’s Nutrition, Bill & Health, Baltimore, MD, USA Melinda Gates Foundation, Seattle, WA, USA; Professor, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
“Population growth is an important driver of economic progress. Every stomach comes with two hands attached. Every mouth is backed by a creative human intelligence. We can solve the problems that are caused by our growing numbers. In fact, we have been doing so for many centuries now.” 32 Steven W Mosher (born 1948), American social scientist and President of the Population Research Institute The magnitude of global Key messages population growth The world’s population reached 7 billion on October 31, 2011 • The speed at which the world’s according to the United Nations Population Fund; according population is increasing is without to the United States Census Bureau, this milestone was precedent and poses a wide range of attained on March 12, 2012.1 In the 1970s, it had been at approximately half this figure. The speed at which the world’s complex challenges for nutritionists, population is increasing is entirely without precedent (Figure agriculturalists and public health 1). It places enormous strain on the planet’s resources, and professionals alike. poses a wide range of complex challenges for nutritionists, agriculturalists and public health professionals alike. • Life expectancy has also increased rapidly, A little over two centuries ago, the world’s population was especially in the developed world. 1 billion (Table 1). It was to grow sevenfold in the ensuing • At the same time as the world’s two centuries. It took just 123 years to double, under the influence of the Industrial Revolution and the accompanying population has been rapidly growing, advances in science and medicine. It took 46 years to double childhood mortality rates have seen a from 2 to 4 billion, but only 39 years to double from 3 to 6 dramatic decline. million; and an additional 1 billion was added 12 years later. • There will be a third more mouths to In part, this dramatic increase occurred due to a feed by 2050. Food production will phenomenon called the “population momentum,” as a larger percent of the population was in its reproductive years have to rise considerably to meet this during the period in question. The World Bank defines demand, and Sub-Saharan Africa will population momentum as: “The tendency for population require special attention. growth to continue beyond the time that replacement-level fertility has been achieved because of a relatively high • Overall population growth will fuel the concentration of people in the childbearing years.”2 Even as growth of urban areas, and the rise of fertility rates began to decline around the 1970–80s due to urban populations will have wide- the effect of family planning programs, the previously high ranging health implications. fertility rates resulted in continuing accelerated population growth. The rate of change in the world population was the highest during the 50-year period from 1925 to 1975, at 100 to 200 percent (Table 1). “The scale, severity and duration of the Assuming a medium fertility variant or at replacement levels, world food problem are so great that a by 2050 the world population will be 9 billion and by 2100, massive, long-range, innovative effort 10 billion (Figure 2). Much of this increase will occur in unprecedented in human history will be developing countries, with the population of high-income required to master it.” countries remaining relatively constant (Figure 3). US PRESIDENT’S SCIENCE ADVISORY COMMITTEE, 1967
Figure 1: World population since 10,000 BCE Chapter 1.2 | Population Growth and Malnutrition 33 Figure 1 | World population since 10,000 BCE 7 6 5 Billion People 4 3 2 1 0 -10000 -8000 -6000 -4000 -2000 0 2015 Source: https://ourworldindata.org/world-population-growth/, accessed July 8, 2016 Figure Figure 2 |2:Estimated Estimated and and projected projected world world population, population, billions, billions, 1950–2100 1950–2100 28 Contant fertility variant High fertility varient Medium fertility varient 24 Instant replacement fertility variant Low fertility varient 20 16 12 8 4 0 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Source: https://ourworldindata.org/world-population-growth/, accessed July 8, 2016 Source: United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects: The 2010 Revision. New York. (Updated: April 15, 2011)
34 Mexico City, one of the world’s megacities Table 1 | World population milestones Year World Population Interval 1804 1 billion 1927 2 billion 123 years later 1960 3 billion 33 years later 1974 4 billion 14 years later 1987 5 billion 13 years later 1999 6 billion 12 years later 2011 7 billion 12 years later Change in population profiles over time In many European countries, the total fertility rate – the countries in Africa and Asia have a high total fertility rate. average number of children a woman will have during her Family planning strategies are urgently needed in these lifetime if she experienced the current age-specific fertility countries, both to limit the number of children born and to rates and if she survived through the end of her childbearing ensure appropriate intervals between births. years – is below the level of 2.0 which is required to replace Meanwhile, life expectancy has grown rapidly, especially in the population without increasing it. In Germany, for the developed world. In the USA, for example, it increased instance, it is only 1.4. In the USA, it stands at just above by 56% for males and 63% for females between 1900 and this figure, at 2.1. China, with its policy of one child per 2000. The proportion of the population aged over 65 is family, had a total fertility rate of 1.7 in 2014, according to projected to more than treble from 7% (111 million people) the World Bank, whereas India scored a higher than to 23% (450 million) by 2050. By 2050, the Western Pacific replacement level at 2.5. Countries in Africa, by contrast, Region will have the second oldest population of all WHO demonstrate a very high total fertility rate, with Niger regions – just below Europe where 25% of the population scoring highest of all at 7.2. With certain exceptions, most
Chapter 1.2 | Population Growth and Malnutrition 35 will be aged over 65. With a projected population of 450 32.9 million), Shanghai (China, 28.4 million), Mumbai (India, million older people by 2050 globally, the Western Pacific 26.6 million), Ciudad de México (Mexico, 24.6), São Paulo Region will have far more older people than any other world (Brazil, 23.2 million), Dhaka (Bangladesh, 22.9 million), region. At the same time as the population growth has been Beijing (China, 22.6 million) and Karachi (Pakistan, occurring and fertility rates have been declining, childhood 20.2 million). Tokyo’s population will grow from its 1970 mortality has been dramatically declining globally. It is figure of 23.3 to 38.7 million, and New York-Newark’s from projected to continue to do so across different regions, 16.2 to 23.6. London, the first great metropolis of the although the decline has slowed somewhat in recent years in Industrial Revolution, will occupy only 36th place, with a Sub-Saharan Africa. population of 10.3 million. Despite the massive increase in the size of existing megacities, more and more of the population Overall population growth will fuel the growth of urban will be residing in smaller urban areas, as these get built in areas, which may become home to 50% of the world’s response to overall population growth (Figure 4). After 2050, population by 2050. The number of megacities is expected to rural populations are predicted to remain stable, while the grow to 36 by 2025, from a baseline of two in 1970 (Tokyo urban population of the planet will continue to grow. [Japan] and New York-Newark [USA]). These two cities are predicted to be accompanied in the top ten by Delhi (India, Figure 3 | Growth in developing v. developed countries 1965–2050 Figure 3: Growth in developing v. developed countries 1965–2050 10 Developing countries Developed countries 8 6 Billion People 4 2 0 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat (2007)
Chapter 1.2 | Population Growth and Malnutrition Figure 4: Urban and rural populations by development area, 1950–2050 Figure 4 | Urban and rural populations by development area, 1950–2050 36 6 More developed regions urban populations More developed regions rural population 5 Less developed regions urban populations Less developed regions rural population 4 Billion People 3 2 1 0 Source: UN, World Urbanization Prospects: The 2011 Revision Aerial view of Shibuya in Tokyo, Japan – the world’s most populous city. Sub-Saharan Africa Sub-Saharan Africa in particular will require special attention. Although the rate of population growth in this region is declining rapidly, it will continue to increase from 770 million in 2005 to 2 billion by 2050. Chronic hunger and malnutrition are already high in Sub-Saharan Africa, and so this region will face a special challenge in the years to come. Vulnerability to climate and dependence on rainwater for irrigation makes the agricultural economy of Sub-Saharan Africa as a whole extremely fragile, and this tendency has been accentuated by lack of appropriate investment in agriculture in recent decades. The development of smallholder farming may be key to the region’s success in the future. There is cause for hope, however, when one reflects that Asia had only two staple crops during the “Green Revolution” masterminded by Norman Borlaug in the 1960s and ’70s: Africa has no fewer than eight. Borlaug, who developed high-yielding, disease- resistant, semi-dwarf varieties of wheat, was credited at the time with saving a billion lives.
37 0 1 2 3 4 5 6 7 8 China, Hong Kong, SAR Lagos, Slovakia Figure Malta Portugal Slovenia the capital Lithuania Germany 1.36 Russian Federation 5: Total TFYR Macedonia Barbados of Nigeria, Serbia Trinidad and Tobago fertility Armenia Belgium seen by Denmark Brazil Bahamas Australia Dem. People’s Rep. of Korea fromcountry, Myanmar USA 2.07 Uruguay Turkey New Caledonia Figure 5 | Total fertility by country, 2005–2010 Guyana Source: UN Department of Economic and Social Affairs – Population Division. Bangladesh the air. The 2005–2010 Réunion Uzbekistan Guam Panama Bhutan Western Sahara Fiji Botswana Laos French Guiana Gabon Zimbabwe city’s population currently stands at 21 million. Micronesia Samoa Guatemala Solomon Islands Côte d’lvoire Eritrea Central African Republic Gambia Equatorial Guinea Niger 7.19 Benin Angola Chad Mali
Chapter 1.2 | Population Growth and Malnutrition Figure 6: Gains in US life expectancy: 1900–2050 Figure 6 | Gains in US life expectancy: 1900–2050 38 90 80 70 Female 0 Male 0 60 Age Female 65 Male 65 50 40 30 1900 1920 1940 1960 1980 2000 2020 2040 Source: Courtesy of Agree, 2011. Figure 7: Childhood mortality, 1950–2050 Figure 7 | Childhood mortality, 1950–2050 330 280 230 Deaths per 1,000 births 180 130 Sub-Saharan Africa South-central Asia 80 World 30 Source: WHO World Population Prospects: The 2004 Revision.
Street scene in India. 39 Urbanization and health The growth of populations living in urban environments has Urban environments also tend to discourage physical activity wide-ranging health implications. One in three urban dwellers and promote consumption of unhealthy, calorie-dense diets lives in slums, where nutrition, sanitation, and air and water that are high in refined carbohydrates such as white flour and quality are usually very poor. This amounts to 1 billion white rice. The process of refining a food not only removes the people worldwide. Urban air pollution kills approximately fiber; it also removes much of the food's nutritional value, 1.2 million people each year around the world, mainly due including B-complex vitamins, healthy oils and fat-soluble to cardiovascular and respiratory diseases. Much of this vitamins. The consumption of the many processed foods that pollution, although not all of it, is attributable to emissions characterize the modern Western diet results in higher from motor vehicles. The incidence of tuberculosis is also much prevalence of obesity, diabetes and related non-communicable higher in big cities. In the Democratic Republic of Congo, for diseases, which account for 63% of deaths worldwide. example, 83% of people with tuberculosis live in cities. Countering these factors, the provision of health services is more efficient in cities; but the growth of urban populations
Chapter 1.2 | Population Growth and Malnutrition 40 will create a host of practical, logistical and financial with greater disparities observable in urban than in rural challenges, placing huge burdens on public health systems in areas. In absolute terms, however, large swathes of the general and healthcare budgets in particular (Table 2). world’s population will still rise out of extreme poverty. Global poverty has declined in the past two decades, and A recent USDA report predicts an improvement in the the global poverty ratio is predicted to fall from its 2005 global food insecurity situation, projecting that only 6% of figure of 21% to 2.5% in 2050. 3 Economic growth has the world population will have inadequate access to food by occurred, but is highly variable within countries, and over 2026, compared to 17% at present. Decreased food prices time will even lead to higher income inequality within and increasing incomes, especially in Asia, may be linked to individual countries. In India, for example, the top 20% of this decline. 5 earners in rural settings can only match the incomes made Population growth is contributing to climate change, which by middle and upper middle earners in cities. The lowest is putting pressure on food systems and will impact earners in urban settings are far ahead of the rural poor, agricultural yields. Food systems themselves contribute who account for 80% of rural populations, and the urban 19–29% of greenhouse gas emissions, and agricultural top 20% of earners far outstrip all other categories.4 production accounts for 80–85% of total food systems Disturbingly, the GINI Index – a measurement of the emissions, although significant variation by country exists. income distribution of a country's residents that helps define The relationship between climate change and nutrition is the gap between the rich and the poor – is increasing in discussed in detail elsewhere in this book. countries with high economic growth and high populations, An escalator in a crowded shopping mall. Economic growth is likely to lead to higher income inequality not just between nations but also within individual countries.
Chapter 1.2 | Population Growth and Malnutrition 41 Table 2 | Implications of change for global health The nutrition transition Confidence Modernization, urbanization, economic development and Health effect level increased wealth are also leading to predictable shifts in diet Increase in malnutrition and consequent High referred to as the “nutrition transition”. This is broadly disorders, including child growth and development. classified into five patterns (Table 3). Increase in death, disease, and injury from heat High Most low-and middle-income countries are currently moving waves, floods, storms, fire and drought. from pattern 3 (end of famine) to pattern 4 (consuming more Mixed effects on malaria, with some Very high energy-dense diets). This shift from traditional diets to contractions balanced by expanded Western-style diets has been a key contributor to the obesity geographic range and change in seasonality. epidemic in low- and middle-income countries. Meanwhile, Change in the range of some vectors of High childhood stunting (low height for a given age), an indicator of infectious diseases. undernutrition in the earliest years of life, and which results in Increase in diarrheal diseases. Moderate increased mortality and cognitive deficits, is still at unacceptably Increase in number of people exposed to Low high levels. Although declines in stunting are observed dengue fever. worldwide, and the MDG target of halving the incidence of Decrease in cereal crop productivity in low Moderate stunting worldwide by 2015 was nearly achieved, 162 million latitudes for even small temperature increases. children were stunted in 2012, with particularly high levels of Source: IPCC Fourth Assessment Report Climate, 2007. Table 3 | The five patterns of the nutrition transition Pattern Description Commentary 1 Hunter-gatherer Individuals live highly active lifestyles, hunting and foraging for food. Diets typically are rich in fibrous plants and high in protein from lean wild animals. 2 Early agriculture Famine is common, slowing individuals’ growth and decreasing their body fat. 3 End of famine Famine recedes as income rises and nutrition improves. 4 Overeating, As income continues to rise, individuals have access to an abundance of high-calorie foods, and obesity-related they become less active, leading to increases in obesity and obesity-related chronic diseases, diseases such as diabetes and heart disease. 5 Behavior change In response to increasing rates of obesity and obesity-related chronic diseases, individuals change their behavior – and communities promote behavior changes – to prevent these conditions. Source: IPCC Fourth Assessment Report Climate, Behavior change prevalence in south Asia, Sub-Saharan Africa, the Caribbean, nutrition transition. This will place considerable demands on and Oceania. Appropriate breastfeeding and complementary the world’s food production systems, and alternative sources feeding practices are key to the prevention of stunting, as are of food, such as fisheries and aquaculture, should be explored. adequate levels of sanitation and hygiene. Outlook Meat consumption, which is important for meeting requirements for intake of animal protein as well as the According to the FAO, there will be a third more mouths to micronutrients iron, zinc and vitamin A, is growing feed by 2050, despite an anticipated decline in fertility rates worldwide. There are, however, vast regional discrepancies across the globe.7 Food production will have to rise by 70% to in levels of meat consumption, with citizens of Bangladesh, meet this need, which will place huge demands both on the Nigeria, Ethiopia, the Democratic Republic of Congo and environment and on the world’s agricultural systems. Burma consuming an average of just 0–10 g meat per day and According to the best-case scenario, 4.5% of the world’s those of the USA, France and The Netherlands consuming population will be malnourished in 2050 (as opposed to 12.4% 70–80 g daily. If the consumption of milk is included, over in 2005); the worst-case scenario puts this figure at 5.9% 70% of the world’s population consumes less than 30 g of (Tables 4 and 5). Approaches to making agriculture more animal protein per day.6 Nevertheless the consumption of innovative, efficient and sustainable, and to ensuring that it meat, vegetable oils, sugar and pulses is projected to increase delivers not just more calories but also improved nutritional in developing countries, many of which are undergoing a content, are discussed in chapters 3 and 4 of this book.
Chapter 1.2 | Population Growth and Malnutrition Table 4 | World food supply and demand projections: best-case scenario 42 WORLD FOOD SUPPLY AND DEMAND IN MARKET FIRST SCENARIO World crop production Crop land Yield Crop loss ratio (million metric tons) (million hectares) (tonnes/hectare) (percent) 2005 4,190 1,544 2.71 30.3% 2050 6,584 1,617 4.07 22.3% percentage change 57.1% 4.7% 50.0% avg ann. percentage change 1.0% 0.1% 0.9% CALORIES AVAILABLE PER PERSON World OECD Non-OCED Sub-Saharan Africa 2005 2,800 3,421 2,662 2,256 2050 3,207 3,635 3,135 2,588 percentage change 14.5% 6.3% 17.8% 14.7% avg ann. percentage change 0.3% 0.1% 0.4% 0.3% PERCENTAGE OF POPULATION MALNOURISHED World OECD Non-OCED Sub-Saharan Africa 2005 12.4% 1.9% 14.8% 30.7% 2050 4.5% 0.0% 5.3% 18.5% Source: Hillebrand E, White Paper, Expert Meeting on how to feed the world in 2050, FAO 2010. Table 5 | World food supply and demand projections: conservative estimates WORLD FOOD SUPPLY AND DEMAND IN TREND SCENARIO World crop production Crop land Yield Crop loss ratio (million metric tons) (million hectares) (tonnes/hectare) (percent) 2005 4,190 1,544 271 30.3% 2050 6,150 1,620 3.8 24.1% percentage change 46.8% 4.9% 39.9% avg ann. percentage change 0.9% 0.1% 0.1% CALORIES AVAILABLE PER PERSON World OECD Non-OCED Sub-Saharan Africa 2005 2,800 3,421 2,662 2,256 2050 3,099 3,648 3,013 2,507 percentage change 10.7% 6.6% 13.2% 11.1% avg ann. percentage change 0.2% 0.1% 0.3% 0.2% PERCENTAGE OF POPULATION MALNOURISHED World OECD Non-OCED Sub-Saharan Africa 2005 12.4% 1.9% 14.8% 30.7% 2050 5.9% 0.0% 6.8% 21.4% Source: Hillebrand E, White Paper, Expert Meeting on how to feed the world in 2050, FAO 2010.
Rice terraces in Longsheng County, Guangxi, China. Feeding the world’s burgeoning population will require innovations in agriculture. 43
Chapter 1.2 | Population Growth and Malnutrition My personal view here. FP2020 is a global partnership that supports the 44 rights of women and girls to decide, freely, and for Michael J Klag themselves, whether, when, and how many children they want to have. FP2020 works with governments, civil Population growth underlies many of the most important society, multilateral organizations, donors, the private challenges facing the world today. In the future, the world sector, and the research and development community to will be more populous, especially in low- and middle- enable 120 million more women and girls to use income countries, more urban, and with an older and contraceptives by 2020. FP2020 is an outcome of the 2012 more obese population which will be characterized by London Summit on Family Planning where more than 20 even greater economic disparities than is the case today. governments made commitments to address the policy, All these trends will impact poor countries more severely financing, delivery and sociocultural barriers to women than wealthy ones. accessing contraceptive information, services and supplies. Donors also pledged an additional US$2.6 billion in Family planning is essential to curb population growth, funding. It is very important that this goal be achieved. and Family Planning 2020 (FP2020) has a key role to play References Further reading 1 http://www.worldometers.info/world-population/, accessed December 14, 2015. Rosen S, Thome K, Meade B. International Food Security 2 http://www.worldbank.org/depweb/english/modules/glossary. Assessment, 2016–2026. A report summary from the Economic html#momentum, accessed July 8, 2016. Research Service. USDA June 2016. http://www.ers.usda.gov/ 3 Hillebrand, E. Poverty, growth and inequality over the next 50 years. FAO, 2010. media/2109786/gfa27.pdf, accessed July 22, 2016. 4 Sen, A (mimeo, 2004) based on NSS data. Vermeulen SJ, Bruce M, Campbell BM. Climate Change and Food 5 Rosen S, Thome K, Meade B. International Food Security Assessment, Systems. Annu. Rev. Environ. Resour. 2012. 37:195–222. http:// 2016–2026. A report summary from the Economic Research Service. USDA www.annualreviews.org/doi/abs/10.1146/annurev- June 2016. http://www.ers.usda.gov/media/2109786/gfa27.pdf environ-020411-130608, accessed July 22, 2016. 6 FAOSTAT 2001. The special challenge for sub-Saharan Africa. High Level Expert 7 FAO Expert Meeting, 2009. Forum – How to Feed the World in 2050. Rome: FAO, October 2013. http://www.fao.org/wsfs/forum2050/wsfs-background- documents/issues-briefs/en/, accessed July 22, 2016. World agriculture: towards 2015/2030 Summary report. FAO, 2002. http://www.fao.org/docrep/004/y3557e/y3557e00.HTM, accessed July 22, 2016. Cleland J, Bernstein S, Ezeh A et al. Sexual and Reproductive Health 3. Family planning: the unfinished agenda. Lancet 2006; 368: 1810–27. http://www.thelancet.com/pdfs/journals/lancet/ PIIS0140-6736(06)69480-4.pdf, accessed July 22, 2016.
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