Global Nutrient Availability: a call for accountability and action
Authors: Emily Rose Smith
Journal: The Lancet Planetary Health (2018)

Malnutrition is a major public health problem underlying global morbidity, mortality, and suboptimal child development. Sustainable Development Goal (SDG) 2 specifically aims to "end hunger, achieve food security and improved nutrition, and promote sustainable agriculture". But better nutrition is linked to each of the SDGs. Maternal and child undernutrition—including micronutrient deficiencies, stunting, and wasting—accounted for nearly half of under-5 child deaths in 2011.1Black RE Victora CG Walker SP et al.Maternal and child undernutrition and overweight in low-income and middle-income countries.Lancet. 2013; 382: 427-451Summary Full Text Full Text PDF PubMed Scopus (4299) Google Scholar Furthermore, overweight and obesity are the fifth-leading risk factors for death globally, and they have had the fastest annualised rate of increase since 1990 of any risk factor.2GBD 2016 Risk Factors CollaboratorsGlobal, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016.Lancet. 2017; 390: 1345-1422Summary Full Text Full Text PDF PubMed Scopus (1650) Google Scholar The ability to track global nutrient availability and intake is essential to ensuring progress toward SDGs, and it is increasingly salient as climate change and geopolitical instability affect food availability worldwide. The Global Nutrient Database (GND) developed by Josef Schmidhuber and colleagues fills an important knowledge gap in global nutrition. This work allows the examination of global nutrient availability from 1980 to 2013 in a standardised way. While the study suggests general improvement in diets and notes increasing nutritional abundance—which might be associated with increasing obesity—it also highlights continued inequality in nutrient availability. According to data from the Food and Agriculture Organization of the United Nations (FAO), global energy availability currently exceeds what is needed to hypothetically end hunger, and Schmidhuber and colleagues show that global energy availability has increased to 2710 kcal per person per day over the past three decades. However, the smallest absolute increase has occurred in low-Socio-demographic Index (SDI) countries (80 kcal per person per day). Similarly, low-SDI countries have seen relatively few increases in protein availability during the same period. High and upper-middle-SDI countries continue to have the highest availability of essential micronutrients, including iron, vitamin A, and zinc. Climate change could exacerbate these inequalities. Elevated CO2 might reduce the nutritional quality of staple crops,3Myers SS Zanobetti A Kloog I et al.Increasing CO2 threatens human nutrition.Nature. 2014; 510: 139-142Crossref PubMed Scopus (762) Google Scholar and a recent simulation study showed that CO2-related iron and zinc deficiencies are projected to disproportionately affect southeast Asia and Africa.4Weyant C Brandeau ML Burke M Lobell DB Bendavid E Basu S Anticipated burden and mitigation of carbon-dioxide-induced nutritional deficiencies and related diseases: a simulation modeling study.PLoS Med. 2018; 15: e1002586Crossref PubMed Scopus (29) Google Scholar Despite improvements in global nutrition availability, inequalities at the national level are clear, and they are persisting. This study—with its novel application of machine-learning methods and use of detailed global data—provides the best estimates of global nutrient availability so far. The FAO's Supply and Utilization Accounts (SUA) database (from which food balance sheets are generated) is the most comprehensive source of data on national food availability.5FAOSupply Utilization Accounts and Food Balance Sheets—background information for your better understanding.http://www.fao.org/economic/the-statistics-division-ess/methodology/methodology-systems/supply-utilization-accounts-and-food-balance-sheets-background-information-for-your-better-understanding/en/Date accessed: July 23, 2017Google Scholar This new study uses the FAO SUA data, the United States Department of Agriculture's (USDA) Food and Nutrient Database for Dietary Studies (FNDDS), refuse factors from USDA handbooks, national food consumption surveys, and advanced analytical methods to provide detailed and useful nutrition information for 195 countries. The study improves on previous efforts in several ways. The FAO food balance sheets used in previous studies only provide aggregated data for total energy intake and data for a limited number of macronutrients and micronutrients; the present study is the first to use the primary source SUA data. The spatiotemporal Gaussian process regression methods used are a sophisticated approach to account for the heterogeneity of data across space and time. Finally, the study team used gradient boosting for applied machine learning to optimise predictive models. Despite the advances in global nutrient intake estimation stemming from the work by Schmidhuber and colleagues, there are limitations to interpreting this work. The novel analyses were validated by comparing them with nutrient consumption data from the USA, Korea, and Ecuador, but these are high-income and middle-income countries with relatively high global food security index ratings.6The Economist Intelligence UnitGlobal food security index 2017: measuring food security and the impact of resource risks. The Economist, London2017Google Scholar The validation countries did not include lower-middle-income or low-income country contexts where industrialised livestock rearing and agriculture are less common and data collection systems are not as strong. Thus, the choice of validation countries likely overstates the validity of the global estimates. Furthermore, there are several potential sources of measurement error in these estimates. For example, FAO SUAs reflect various national datapoints, all of which are prone to error. Previous work comparing FAO estimates to national or regional dietary intake data has identified significant heterogeneity by region, as well as by age, sex, and data collection period.7Del Gobbo LC Khatibzadeh S Imamura F et al.Assessing global dietary habits: a comparison of national estimates from the FAO and the Global Dietary Database.Am J Clin Nutr. 2015; 101: 1038-1046Crossref PubMed Scopus (90) Google Scholar Furthermore, Schmidhuber and colleagues' methods assume standard nutrient content (based on US data) and standard inedible food proportions across countries. The data reflect neither homestead agriculture production, nor micronutrient fortification programmes. While this new work might provide the best-yet estimates of nutrient availability, it does not provide data on global nutrient intake data, which is based on food affordability, availability, and quality.6The Economist Intelligence UnitGlobal food security index 2017: measuring food security and the impact of resource risks. The Economist, London2017Google Scholar Finally, national estimates mask significant inequality at the subnational level. Future research should address these limitations. Given the importance of malnutrition in global health and development, as well as the paucity of national data regarding dietary intakes and micronutrient deficiencies, the GND represents a major advance. The GND provides a standardised method for assessing changes over time and across countries. This is essential for tracking global progress in reaching SDG 2, and for monitoring food security in the context of climate change and geopolitical instability. Furthermore, these results highlight opportunities to fill existing macronutrient and micronutrient gaps through food system interventions. These range from large-scale food fortification to targeted production of livestock or staple crops and improvement of the food safety net.8Masters WA Rosettie K Kranz S et al.Priority interventions to improve maternal and child diets in sub-Saharan Africa and South Asia.Matern Child Nutr. 2018; 14: e12526Crossref PubMed Scopus (9) Google Scholar Nutrition, health, agriculture, and climate change stakeholders should consider these data and analyses as an opportunity to ensure targeted action and accountability to improve nutrition globally. I declare no competing interests. The Global Nutrient Database: availability of macronutrients and micronutrients in 195 countries from 1980 to 2013Our global nutrient database provides a picture of the supply of various nutrients at the country level and can be useful to assess the performance of national food systems in addressing the nutritional needs of their population. Full-Text PDF Open Access