The global food supply is becoming more vulnerable to climate change-related threats because people around the world increasingly eat a similar and narrow diet, scientists say.
Higher living standards in the developing world – especially eating more protein and fat – are leading to a standard global food supply consisting of a comparatively short list of crops, meat and dairy products, according to an international study.
The researchers warn that this threatens future food security by leaving producers more at the mercy of major threats like drought, insect pests and diseases, which are likely to worsen because of climate change. It also suggests this changing diet could accelerate a global increase in obesity, heart disease and diabetes.
They have called for action to be taken to encourage the growth of a wider range of crops and varieties of crops, as well as steps to make staple foods more nutritious and better teaching about a healthy diet. Luigi Guarino, of the Germany-based Global Crop Diversity Trust (GCDT), who co-authored the report, said: “As the global population rises and the pressure increases on our global food system, so does our dependence on the global crops and production systems that feed us. The price of failure of any of these crops will become very high.”
The research, published in the Proceedings of the National Academy of Sciences (PNAS) journal found that human diets have become 36 per cent more similar in the last 50 years.
It used data from the Food and Agriculture Organisation of the United Nations (FAO), looking at more than 50 crops in more than 150 countries which account for 98 per cent of the world’s population, between 1961 and 2009.
More people are consuming more calories, protein and fat, and they rely increasingly on a short list of major food crops, like wheat, maize and soybean, along with meat and dairy products, for most of their food
Several crops that were important half a century ago remain so – including wheat, maize, rice and potatoes. They have been joined as staples by newcomers including soybean, sunflower oil and palm oil.
But other formerly widespread crops, including cereals like sorghum, millet and rye, and root crops like sweet potato, cassava and yam have seen a drop in consumption.
People living in some areas, especially Africa and Asia, are eating an increasing range of staple foods, but they are adding ones which are already widely eaten elsewhere, like wheat and potatoes.
The study claims wheat is now a major staple in 97.4 per cent of countries.
The changing diet is being driven by increased development in the Third World, which is leading to greater urbanisation, higher incomes and trade liberalisation, which allow access to – and money to buy – a wider range of foods.
“More people are consuming more calories, protein and fat, and they rely increasingly on a short list of major food crops, like wheat, maize and soybean, along with meat and dairy products, for most of their food,” said study lead author Colin Khoury, from the Colombia-based International Centre for Tropical Agriculture (CIAT).
“These foods are critical for combating world hunger, but relying on a global diet of such limited diversity obligates us to bolster the nutritional quality of the major crops, as consumption of other nutritious grains and vegetables declines.”
The study was carried out by scientists from CIAT, GCDT, Wageningen University in the Netherlands and the University of British Columbia in Canada.