and very few pulses or beans. Our diets overall are becoming sweeter and oilier and meatier and we are highly dependent for our sustenance on foods that have been grown or produced far away from the place where we live, wherever that place might be. Khoury and his colleagues have calculated that more than two-thirds of national food supplies across the world are derived from crops that are foreign to the country where they are eaten.25
One grey rainy spring morning I am talking with Colin Khoury over the phone. He is at his home in Colorado, where he works at the US National Seedbank. His background, he explains, is not in nutrition but in plant science. ‘I’m a diversity person,’ he says – one of the many biologists who believe that the future of the planet depends on maintaining the maximum biodiversity for healthy ecosystems. As he and his colleagues began to draw together all the data on the world’s food supply, Khoury was startled to see just how homogenous the global diet had become, with eaters tending towards a common mean.
In Denver, where Khoury lives, the breakfast burrito is a local favourite in diners and cafés, especially at weekends. This greasy and comforting wrap is made from flour tortillas stuffed with eggs, potatoes, green chillis, maybe cheese and some kind of meat – sometimes chorizo, sometimes bacon or steak. The sandwiches are an object of local pride, like the Philadelphia cheesesteak.
To those who love it, the Denver breakfast burrito is a distinctive thing. But in another sense, this ‘local’ American speciality is not local at all. The bacon and the eggs come from giant production lines in Iowa. The eggs are fried in soybean oil from Brazil. As for the wheat that makes the tortilla that binds the whole meal together, it is the same dusty refined white flour made from the same flavourless modern strain of wheat that goes into most breads in America, from bagels to sliced Wonderbread to hotdog buns. The ingredients may be shuffled differently, but the Denver breakfast burrito is built from much the same deck of cards as a New York hamburger and fries or a pepperoni pizza in the Philippines.
‘People are eating much more of the same crops,’ Khoury tells me. ‘We have all these local twists on food but underneath it is not a huge list of species.’ In a way, the leap into stage four is like the emergence of agriculture in stage two: a narrowing of the diet which brings new diseases in its wake.
When you strip away the packaging, the recipes and the brand names, most humans – from Rio to Cairo – are getting a sizeable majority of our energy from meat, sugar, refined wheat, rice and refined vegetable oil. The average global eater largely consumes certain staple items, most of which will have been internationally traded before they reach the shop or the plate. The average eater gets the bulk of his or her daily calories (1,576) from just six sources. These are:
1 animal foods
2 wheat
3 rice
4 sugar
5 maize
6 soybeans
Of these, animal foods and wheat each contribute around 500 calories, with a further 300 calories apiece coming from rice and sugar, 200 calories from maize and 76 calories from soybeans. Compared to these big six items, all the other food commodities pale into insignificance.26
There has been a startling shift away from multiple traditional diets towards a single modern one, with the same sweet-salty flavours and the same triumvirate at its heart of rice, wheat and meat.
You can trace the effects of these homogenous diets all the way to the gut. Compared to the average affluent Westerner, a hunter-gatherer from the Hadza tribe in north-central Tanzania – subsisting on an ever-changing diversity of roots and berries and wild meats – has 40 per cent more microbiome diversity (the microbiome being the host of micro-organisms in the human gut). Having a less diverse gut microbiome has been linked with both obesity and type 2 diabetes.27
It’s worth noting that in some countries the move towards a global average diet has been beneficial. ‘In some places,’ Khoury points out, ‘it actually means an increase in diversity,’ certainly compared to fifty years ago. Averaged out, the world’s diet is more balanced now than it was in 1960, if balance is defined as eating an even spread of different foods. Until recently, many countries in east Asia were dangerously dependent on the single staple of rice to feed themselves. Apart from being a monotonous way to live, such single-staple diets are precarious when the single crop happens to fail – as the Irish potato famine demonstrated in the nineteenth century. Thanks to the opening up of new global markets, east Asian countries such as Vietnam have now been able to diversify into wheat and potatoes, which bestows greater food security as well as more varied nutrients.
But in most places, the new global diet has involved a narrowing down of what people eat. Our world contains around seven thousand edible crops, yet 95 per cent of what we eat comes from just thirty of those crops. As omnivores, humans are designed to eat a varied diet, so there’s something strange and wrong when, as a species, we become so limited in our choice of foods.28
It might surprise you to learn (it did me) that the most average place in the world, food-wise, is not the United States, which is actually pretty extreme in the composition of its diet. To take one example, Americans have access to around twice the global average calories from meat (around 1,000 calories as against 500). Americans also consume far more sugar and sweeteners than the global mean.
To find the most average eaters in the world, you need to look to some of the middle-income countries of the developing world, especially in Latin America. These countries seem to hold up a mirror to the way food consumption is now shifting to a global mean. Purely in terms of the crops consumed, one of the most average places in the world for food is Colombia. Here, the top four sources of calories used to be maize followed by animal products followed by sugar and rice. Now the order is changed. Top of the list of Colombian foods are animal products (518 calories) followed by sugar (404 calories), then maize (368 calories) and rice (334 calories). Compared with the 1960s, people in Colombia have access to far more wheat and sugar and more refined oils.29
The idea that Colombians eat in anything like an average way would once have seemed laughable. Until recently, Colombians’ food habits were not merely different from those of Europe and the US, but distinct to the point of eccentricity from the rest of Latin America. There is nothing ‘average’ about a country where people eat milk soup with eggs for breakfast, garnished with spring onions and coriander leaf. Called changua, to those reared on it this soup is as soothing as congee or chicken soup. Another distinctive element of Colombian food was its unique and abundant range of tropical fruits.
On a trip to Spain in the spring of 2017, I got into conversation with the best-selling Colombian writer Héctor Abad (author of the magical and strange book Recipes for Sad Women). We strolled through the city of San Sebastián just before sunset and Abad told me of his love of old books and old ways. He recalled that when he first travelled from Colombia to Italy, he was astonished to find that Italians ate fruit at the end of the meal rather than at the start. In the Colombia of Abad’s youth, local fruit was the opening of every dinner for those who could afford it. The fruits of Colombia range from succulent pink guavas to guanábanas, which Abad later described to me in an email as ‘a fruit with the peel of a dinosaur, and the meat a sweet humid cotton that you can easily chew’.
When Abad was eight years old, in the 1960s, an American student called Keith came to visit his family. Keith ‘almost vomited’ when Héctor’s mother offered him changua soup for breakfast. Keith was also no fan of arepas, the Colombian corn bread which used to be ground and roasted and baked fresh every day. Keith complained that in the city of Medellín there was not one place to get a hamburger. Abad was a teenager before he first tasted ‘that strange and very caloric thing called pizza’.
These days, Abad and his wife still eat the good old foods of Colombian cuisine, or as many of them as they can find. They cook a lot of soups and fish or hearty dishes of meat, rice and vegetables. But such dishes are no longer the norm for Colombians. Abad is convinced that if Keith came back to Colombia now, he would have no problem finding foods just like the ones he ate back home in Los Angeles.
Abad