The Changing Global Diet
Food supplies around the world have changed dramatically in the past 50 years. Scroll below to learn more about global change in the diversity of crops we eat.
Click the links at left to explore food supply diversity change in specific countries, compare countries to one another, learn about the changing importance of particular food crops, see how similar food supplies around the world are becoming, and compare the diversity within countries’ modern day food supplies.
Diets around the world have become more similar
The Changing Global Diet story
How many crops feed the world? How diverse is the global diet? What changes are happening in different countries’ food supplies over time? Follow the storyline below to see our exploration of these questions.
We studied the changing contributions of all 53 crop commodities measured in United Nations Food and Agriculture Organization statistical data (FAOSTAT) that contribute to calories, protein, fat, and food weight in national per capita food supplies. Animal foods were included as a single commodity where needed to place the findings in the context of the total food supply.
We studied the food supplies of 152 countries, representing 98% of the world’s population. To study as much of the world as possible across the entire time series (1961 to 2009), we standardized areas that changed over the past 50 years, for example by recombining the countries formerly in the USSR and Yugoslavia.
National diets became larger
We found that, on average, countries’ food supplies from both plant and animal sources consistently grew over the past 50 years in terms of calories, protein, fat, and food weight. Oils as a food group had the most dramatic increase.
National diets became more diverse
Around the world, countries added new food crops to their diets. Countries’ food supplies incorporated an average of nine new crop commodities contributing to calories, six to protein, five to fat, and ten to food weight.
National diets became more balanced
Most countries’ food supplies increased in evenness, meaning that each crop in the food supply contributed more equally to the diet.
The evenness scale refers to Pielou’s Evenness Index, where 0 is a diet totally dominated by a single food, and 1 is a diet where all foods contribute an equal amount.
The most dominant foods in national diets became less important
The proportion of countries’ food supplies comprised of the most abundant crop commodity declined on average. Particularly notable reductions in originally very high levels of dominance were visible in rice in contribution to calories in Southeast Asia, coconut for fat in Pacific Island countries, and groundnut for fat in Central African countries.
The dominance scale refers to percent contribution to the national food supply by the most important food (whichever it is), where 0 means no contribution, and 1 means 100% contribution to the food supply.
National diets became more similar worldwide
As countries’ food supplies became more diverse in number of crop commodities, and the contribution of each of the crops became more even, food supplies worldwide became more similar. East and Southeast Asian as well as sub-Saharan African countries underwent the greatest changes toward a global average diet.
The similarity scale refers to an adapted Bray-Curtis Dissimilarity distance, which measures the distance in the composition of the food supply (both crops and animal products) in each country to the global average diet, where 0 means very different from the global average, and 1 means completely equal to the global average diet.
Interested in exploring further? Click the links at left to investigate food supply diversity change in specific countries, compare countries to one another, learn about the changing importance of particular food crops, see how similar food supplies around the world are becoming, and compare the diversity within countries’ modern day food supplies.
Colin K. Khoury
This work is associated with the publication:
Khoury CK, Bjorkman AD, Dempewolf H, Ramírez-Villegas J, Guarino L, Jarvis A, Rieseberg LH and Struik PC (2014). Increasing homogeneity in global food supplies and the implications for food security. PNAS 111(11): 4001-4006. doi: 10.1073/pnas.1313490111.
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