Food supply scores

We summarized the availability of 18 food groups into numerical scores that characterize food systems in different countries and years. Figure 1 and Supplementary Fig. 1 show how the scores relate to the availability of specific foods, that is, the proportion of total energy available for human consumption from each food group; Supplementary Table 1 lists the individual food items in each group. The first score represents food systems characterized by animal source and sugar-based foods, and is higher where meat, milk, animal fats, eggs, offals and sugar and sweeteners are a more abundant part of the food supply, and lower where cereals make up a larger share of the food supply. The vegetable score is higher in food systems characterized by an abundance of vegetables, vegetable oils, treenuts and eggs. The starchy root and fruit score is higher in food systems with an abundance of these two foods, and decreases with abundance of cereals. Finally, the seafood and oilcrops score is higher in food systems that have an abundance of these foods. Almost 90% of the cross-country variation in food availability from 1961 to 2013 is explained by these four scores, which demonstrates their ability to characterize national food supplies parsimoniously and coherently.

Fig. 1: Loadings of each food group for the four food supply scores. Warm colours indicate that an abundance of a food type as a component of the total energy from the food supply increases the scores and an absence decreases the scores; cold colours indicate that absence increases the scores and abundance decreases the scores. Full size image

Current food supply patterns and change over time

Figure 2 and Supplementary Table 2 present mean food supply scores by country for the period 2009–2013, and changes from 1961–1965 to 2009–2013. Although a food system characterized by a high supply of animal source foods and sugar is viewed as representing a typical affluent Western population17,19, and the highest scores for this pattern in 2009–2013 were seen in Iceland and Denmark, the scores were also high elsewhere, for example, in Argentina, Kazakhstan and Mongolia. The animal source and sugar score was low in most countries in sub-Saharan Africa and south Asia, with the lowest values seen in Burundi and Rwanda, whereas Latin American countries had a mix of low and high scores. The animal source and sugar score increased most over the half-century in China, followed by countries in southern and eastern Europe, east Asia and parts of central Asia. Meanwhile, six of the nine largest decreases took place in high-income English-speaking countries (that is Australia, Canada, Ireland, New Zealand, the United Kingdom and the United States of America). The cross-country variations in the score were similar in 1961–1965 and 2009–2013 (Supplementary Table 3).

Fig. 2: Mean food supply scores by country. a,b, Scores by country for the period 2009–2013 (a) and the change from 1961–1965 to 2009–2013 (b). No data were available for countries shown in grey. As described in Methods, the scores are presented on a scale of 0 to 100 in which 0 represents the lowest value observed in any country from 1961 to 2013, and 100 the highest. Full size image

The vegetable score was highest in the ‘Silk Road’ band that stretches from east Asia (China and South Korea), through west Asia (Iran) to the Mediterranean (Lebanon and Greece). The lowest vegetable scores were seen in parts of sub-Saharan Africa, for example, Chad and Lesotho, and some Pacific islands, for example, Solomon Islands; the scores were also consistently low across Latin America. The largest increases in the vegetable score over the past half-century occurred in east Asia and parts of the Middle East, with a change of +75 in South Korea. Decreases in the score were typically small, and occurred largely in sub-Saharan African countries, which included Guinea and Sierra Leone. The cross-country variation of this score increased between 1961–1965 and 2009–2013 (Supplementary Table 3).

The starchy root and fruit score was highest in tropical sub-Saharan Africa, with the seven highest scores appearing in this area. It was lowest in east and south Asia, particularly in South Korea. In contrast to the animal source and sugar and vegetable scores, there was little change in the starchy root and fruit scores over time, and their variation decreased. Finally, the seafood and oilcrops score was high in South Korea and Japan, and in diverse island nations in the Pacific, Indian and Atlantic Oceans (for example, Kiribati, Seychelles, Iceland, and Bermuda); it was lowest in landlocked Burundi and Mongolia. Over time, the share of seafood and oilcrops in the food supply increased in parts of east Asia, particularly in South Korea (+62) and China.

Relationships between changes in scores

Correlations between changes in the food supply scores from 1961–1965 to 2009–2013 ranged from close to zero to moderately positive (Table 1). The moderate correlations between the changes in vegetable scores and both animal source and sugar scores and seafood and oilcrops scores were driven by heterogeneous changes in different food groups across countries (Supplementary Figs. 2 and 3). For example, the vegetable score increased in both east Asia and high-income Western countries. However, although east Asia also experienced a large rise in the animal source and sugar score, many Western countries, especially high-income English-speaking countries, experienced declines.

Table 1 Correlations between changes in food scores from 1961–1965 to 2009–2013 Full size table

Overall change in national food supply

The index of overall change in food supply, which combines changes in the four scores, shows clear regional patterns (Fig. 3). The greatest changes in food supply from 1961–1965 to 2009–2013 occurred in east and southeast Asia, especially in South Korea, China and Taiwan, and in parts of the former Soviet Union and the Middle East. In high-income Western countries, the largest changes took place in six southern European countries (Cyprus, Portugal, Greece, Spain, Malta and Italy), and in some high-income English-speaking countries (for example, Australia and Canada). The countries with the smallest changes in their food supply were in sub-Saharan Africa (for example, Mali, Chad and Senegal), Latin America (for example, Argentina) and south Asia (for example, Bangladesh).

Fig. 3: Overall change in national food supply from 1961–1965 to 2009–2013. This index is a weighted sum of the absolute values of change in the four food supply scores. The weights are the proportion of the total variance explained by each score, normalized to add to one. No data were available for the countries shown in grey. Full size image

Strengths and limitations

The main strength of our work is its novel scope of developing data-driven scores that characterize national food systems and have clear interpretations. Furthermore, we used a comprehensive open-source dataset with global coverage over a long time period. However, our analysis also has some limitations. The Food and Agriculture Organization (FAO) Food Balance Sheet data are estimates of food availability, which may be substantially different from food consumption20, and do not capture food waste or subsistence production; nor do they account for food processing, which may have health consequences above and beyond differences in the availability of food groups21. The FAO Food Balance Sheet data are provided at the national level, and therefore do not account for within-country heterogeneity. Additionally, there were no data available for some countries and territories, which include a number of Pacific islands (for example, American Samoa and Nauru) in which major changes to dietary patterns have consequences, such as obesity and diabetes, that are of particular concern22,23,24,25. Where data are available, the FAO acknowledges that data quality varies among countries and items, and over time26.