The downside of farming, however, was that it gave people a less varied range of foods than before. Along with the adoption of staple cereals, phase two saw a rise of famine and a sudden increase in diet-related problems. With diets that were often inadequate both in quantity and quality, humans shrank in stature and suffered from a range of deficiency diseases. The difference in human health between the diets of stage one and stage two is the rationale behind the popular ‘Paleo diet’ in which modern dieters try to turn the clock back by ten thousand years or so and eat as if farming had never been invented.
Then again, to find a diet healthier than the one most people eat today, we don’t need to go back thousands of years. In Europe, we could go back a mere couple of hundred years to the third stage, which Popkin calls ‘receding famine’. During this period, advances in agriculture such as crop rotation and fertiliser led to a more varied and plentiful diet, with fewer starch-based staples and a bigger variety of vegetables along with animal protein. In stage three, the possibilities of cooking expanded, with new methods of drying and preserving and pickling. This period also witnessed a slow decline in mortality. Many of the old deficiency diseases – such as scurvy and beri beri – became less common as diets became more nourishing. On Popkin’s model, many sub-Saharan African countries are living through this stage now. This would explain why their diets compare so favourably, in Imamura’s paper, with those of the industrialised world.
But then comes stage four, which is where we are now. This era is different in quality from any of the other stages. Suddenly, the diet changes much more rapidly, with consequences for human health which are more extreme. The economy shifts away from manual labour and towards mechanisation, people move from the countryside to cities and they start to expend less energy. There are revolutions in food processing and marketing and people start to eat more fat, more meat and more sugar, with far less fibre. Stage four sees human life expectancy hit new highs with the decline of deficiency diseases and the breakthroughs of modern medicine. But it also sees populations suffering from diet-related chronic illness as never before. The ‘nutrition transition’ happened all over the Western world in the decades after the Second World War and is now happening even faster among low- and middle-income nations in the rest of the world. This transition explains why our food is sickening us now, through excess rather than hunger.
Stage four is a radical break with the past which represents a reinvention of food and what it means for human life. One of the greatest departures of stage four is the new homogeneity of food. As agriculture becomes a vast international form of trade, people start relying on the same small number of global crops, even when they live oceans and continents apart.
For centuries, eaters have marked high days and holidays with moreish fried foods such as fritters and doughnuts. Only in modern times, however, could a person buy a stackable carton of fried crisps made from a slurry of dried potatoes and wheat starch seasoned with barbecue flavouring and sit on a sofa eating them not for a celebration, not even out of hunger, but just out of a mild feeling of restless boredom. Only in stage four could another person – in the same mildly bored state – be eating exactly the same crisps at the exact same moment on another sofa somewhere halfway across the world.
The Global Standard Diet
The nutrition transition has not just taken place at the level of supply. It has also altered our personal hungers so that we become people who gravitate towards the same foods. Between the 1960s and today, people around the world stopped depending so much on their own particular foodstuffs, the ones that belonged to our own families and homeland, and started eating other, alien commodities, grown in faraway places. Soon, we were eating so many of these alien foods that they stopped tasting strange to us and starting tasting normal. We changed not only the dishes we ate but the basic composition of our diets.
Nations have adjusted their food habits many times before – after all, tomatoes are not native to Italy, nor tea to Britain – but the recent global homogenisation of taste is unprecedented. All at once, billions of eaters in disparate places have started eating from the same repertoire of ingredients. Never before has such dietary change happened on such a scale, and simultaneously across most of the planet. It is a switch so pervasive and so huge that we haven’t had time to react or even to notice exactly what has changed. It is as if the colour of the sky morphed from blue to green, but before we could protest that something was not right, our eyes adjusted and we carried on as normal.
In the past, it was a fundamental fact about human beings – and about food – that people ate different things in different places. It’s in our nature as omnivores to be skilled at adapting to varied food environments. If you ask someone ‘what’s food?’ you would expect to receive wildly different answers to the question whether you were in Lagos or in Paris. In the past ‘food’ was not one thing but many, varying according to local crops, local ingredients and local ideas and prejudices.
When I was a child in the 1980s, I remember grown-ups in Britain talking with horror about the fact that the Japanese liked to eat … raw fish! It seemed so improbable. From their tone of baffled revulsion, these Britons might as well have been contemplating swallowing live frogs. I never imagined that one day those same grown-ups, older and greyer, would stroll into a perfectly normal shop on the average British high street and casually pick up a tray of sushi for lunch. We now live in a clone-world where you can get pizza in Beijing and Chinese dumplings in Rome, and not even be startled by the incongruity.
At a cultural level, some of this change has been wonderful to see (and to eat). So many of the old barriers and prejudices that kept people from experiencing each other’s food have been ripped apart. Many Westerners who used to look with suspicion on anything too garlicky or spicy or strong will now happily eat Korean-spiced barbecue or fiery Thai curries.
But if our palates have widened in some ways, they have narrowed in others, particularly at the level of ingredients themselves. When ‘food’ becomes a common language across the whole planet it stops being food at all, as our ancestors would have understood it. No matter where on the planet we live, there’s a striking convergence going on in our eating habits.
In the early 2010s, a team of researchers led by Colin Khoury, an American plant diversity expert, set out to quantify how the world’s diet had changed over the past roughly fifty years from 1961 to 2009, using food supply data from the FAO. For every country about which they could gather evidence (152 of them, representing 98 per cent of the world’s population), they measured which crops were eaten and how many per capita calories and other nutrients each of the foods delivered. Overall, the researchers looked at fifty-three different foods, from oranges to rice, from sesame seeds to corn.23
These researchers found that there had been massive changes in eating since the 1960s. Wherever in the world you happen to live, you will now have access to much the same menu of core ingredients as someone who lives a thousand miles away in any direction. Khoury’s team referred to this phenomenon as the Global Standard Diet.24
I started scrolling through the data on the FAO website trying to ascertain how the ‘average’ global eater in the 1960s differed from the average eater today. Then I realised the very question I was asking was wrong. The whole point is that in the 1960s, there was no such thing as an average eater across most countries, just lots of specific and wildly divergent patterns of eating. Back then, there were maize eaters in Brazil and sorghum eaters in Sudan. There were steak and kidney pie enthusiasts in Britain and goulash devotees in Hungary. But it made little sense to ponder how a globally average person might eat because no such person existed.
It is only now that we can, following Khoury, speak of a Global Standard Eater, because it is only now that humans have come to eat in such startlingly similar ways. Perhaps the biggest change is in the quantities that we eat – around 500 calories on average more per day than our equivalents in the 1960s (from 2,237 calories in 1961 to 2,756 calories in 2009).