Global trends in dietary micronutrient supplies and estimated prevalence of inadequate intakes

Abstract

Understanding dietary patterns is vital to reducing the number of people experiencing hunger (about 795 million), micronutrient deficiencies (2 billion), and overweight or obesity (2.1 billion). We characterize global trends in dietary quality by estimating micronutrient density of the food supply, prevalence of inadequate intake of 14 micronutrients, and average prevalence of inadequate intake of these micronutrients for all countries between 1961 and 2011. Over this 50-year period, the estimated prevalence of inadequate intakes of micronutrients has declined in all regions due to increased total production of food and/or micronutrient density. This decline has been particularly strong in East and Southeast Asia and weaker in South Asia and sub-Saharan Africa. Sub-Saharan Africa is the only region where dietary micronutrient density has declined over this 50-year period. At the global level, micronutrients with the lowest levels of adequate estimated intake are calcium, iron, vitamin A, and zinc, but there are strong differences between countries and regions. Fortification has reduced the estimated prevalence of inadequate micronutrient intakes in all low-income regions, except South Asia. The food supply in many countries is still far below energy requirements, which suggests a need to increase the availability and accessibility of nutritious foods. Countries where the food energy supply is adequate show a very large variation in dietary quality, and in many of these countries people would benefit from more diverse diets with a greater proportion of micronutrient-dense foods. Dietary quality can be improved through fortification, biofortification, and agricultural diversification, as well as efforts to improve access to and use of micronutrient-dense foods and nutritional knowledge. Reducing poverty and increasing education, especially of women, are integral to sustainably addressing malnutrition.

Fig 1. Global trends in national food supplies from 1961 to 2011.

(A) Per capita daily energy availability, (B) Micronutrient Density Index, and (C) Estimated Prevalence of Inadequate Micronutrient Intake Index for the world and 7 regions. Trends are based on a five-year moving average. Color-coded triangles represent the value for each region in 2011 when including the contribution of fortification. *WCANA stands for West Central Asia and North Africa; “High Income NES” stands for High Income countries not elsewhere specified (Australia, Canada, New Zealand, United States, and Western Europe).

Fig 2. Country-level Micronutrient Density Index for the years 1961, 1986, and 2011.

Values for countries with missing data (Libya and DRC) were estimated based on the values of neighboring countries.

Fig 3. Country-level estimated Prevalence of Inadequate Micronutrient Intake Index (PIMII) for the years 1961, 1986, and 2011.

For 2011, the PIMII when including the contribution of fortification is also shown. Values for countries with missing data (Libya and DRC) were estimated based on the values of neighboring countries.

Fig 4. Per capita daily energy availability versus the estimated Prevalence of Inadequate Micronutrient Intake Index for all country-years, excluding fortification.

Gray points represent values for every country-year between 1961 and 2011. The thick black line shows a smooth-spline model fitted with these data. Smooth spline model-derived lines for each country are also shown, color-coded by select regions. Black open circles represent values for every country in 2011. Black solid points and ISO3 codes are shown for the 5 largest country outliers in 2011 in either direction relative to the smoothed-spline model for the world: ZWE (Zimbabwe), LBR (Liberia), BGD (Bangladesh), LSO (Lesotho), IDN (Indonesia), RWA (Rwanda), SDN (Sudan), ATG (Antigua and Barbuda), GRD (Grenada), and BHS (Bahamas). “High Income NES” stands for High Income countries not elsewhere specified (Australia, Canada, New Zealand, United States, and Western Europe).

Fig 5. Estimated prevalence of inadequate intake of 11 micronutrients between 1961 and 2011 for the world and 7 regions.

Trends are based on a five-year moving average. Color-coded triangles represent the value in 2011 when including the contribution of fortification. *WCANA stands for West Central Asia and North Africa; “High Income NES” stands for High Income countries not elsewhere specified (Australia, Canada, New Zealand, United States, and Western Europe).

Fig 6. Country-level estimated prevalence of inadequate intake of 9 micronutrients in 2011, including the contribution of fortification.

Values for countries with missing data (Libya and DRC) were estimated based on the values of neighboring countries.