The Way We Eat Now. Би Уилсон

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СКАЧАТЬ Until recently, it was common for women in much of the world to suffer from severe arthritis in their upper bodies, caused by the hours they put in at the grindstone, and rolling dough for such staples as chapattis and tortillas.

      Moreover, not all great-grandmothers were eating an ideal diet. Many of our recent ancestors, as we’ve seen, were eating an extremely monotonous diet of grains and teetering on the brink of hunger. True, your great-grandmother wouldn’t recognise ‘sports drinks’ or popcorn fried chicken or any of the myriad other new highly processed foods, but she also might not recognise many of the wholesome new foods that contribute to health: raw kale salad and overnight oats and pumpkin seeds. Some great-grandmothers, moreover, were eating an early twentieth-century version of junk food. In 1910 a public health campaigner in New York City watched school children buying hotdogs dyed with violently pink food colouring and frosted cupcakes. It’s simply not true that our great-grandmothers would only recognise meat that was organic or grass-fed.

      There is yet another difficulty with calling on the wisdom of our great-grandparents to save us from the worst excesses of modern food. This way of thinking ignores the fact that we are already living and eating with one foot in the past. Many of our most profound problems with eating stem from our inability fully to adapt to the new realities of the nutrition transition. In many ways, we already are eating according to the wisdom of our great-grandmothers, whose physiology and attitudes to eating were forged by the constant threat of scarcity.

      What we eat may have radically changed in our lifetimes, but our food culture has not changed quickly enough to keep pace. We may, sadly, have forgotten the recipes of our great-grandmothers. Most of us have lost their home-spun knowledge of how to bottle fruits for the winter, not to mention their brilliance with a carving knife. But what we have not forgotten is their excitement at a laden table. We are living in a world of perpetual feast but with genes, minds and culture that are still formed by the memory of a scarce food supply. This is part of what it means to live through the vertiginous changes of stage four. We haven’t yet developed the new strategies for living that would enable us to navigate our way through this forest of seeming plenty to a way of eating that gives us both health and pleasure.

      Think about some of the eating strategies that would have made sense in an era of scarce food. For one thing, you would value energy-dense foods such as meat and sugar very highly and gorge on them when they came your way – just as many of us still do. You would leave a clean plate and when food was accessible, you would grab it while you could.³

      Development experts speak of ‘mismatch’ in explaining the clashes between the new food reality and the persistence of a human biology and culture adapted to earlier times. Instead of looking backwards to some imagined past which we can never reclaim, we need to look forwards and have yet another change of taste.

      Our food system is currently full of mismatches. Some of these mismatches are cultural, as we fail to adapt to the new realities of eating in an age of abundance. Our food culture remains far too misty-eyed about sugary foods, for example. We haven’t adjusted emotionally to the fact that sugar is no longer a rare and special celebration food, worthy of devotion. Nor have we yet modified our attitudes towards those who are overweight and obese, to reflect the fact that these people are now in the majority.

      Perhaps the most tragic mismatches are biological, as bodies formed for an environment of scarcity have not adapted to cope with the strange and bountiful new world we now find ourselves eating in.

       The thin-fat baby

      It was 1971 and Dr Chittaranjan Yajnik was a young medical student training at Sassoon General Hospital, Pune, a big city in the west of India. Yajnik was given the task of measuring the body mass index (BMI) of diabetic patients. This should have been a routine job, little more than number crunching. The main challenge was that Yajnik could not afford a calculator, so he laboriously wrote down the patients’ weight in pounds and height in feet in a log table and used his paper notes to calculate in his head the BMI in kilograms per metre squared.⁴

      After taking measurements for the first ten patients, Yajnik noticed something was not right about his numbers. His medical textbooks had taught him that type 2 diabetes was a disease mostly suffered by the old and the obese. But the first ten diabetic patients that Yajnik measured in the hospital at Pune were all young and thin, with low BMIs. If his measurements were correct, then the textbook must be wrong, or at least incomplete, in its definition of type 2 diabetes as an offshoot of old age and obesity. Yajnik tried to raise the problem with his medical supervisor but was told that this was no time to be challenging medical orthodoxy – he should just focus on passing his exams.⁵

      Yajnik could not put the puzzle of diabetes in India out of his mind. After some years studying Western diabetes in Oxford, England, he returned to Pune as a fully qualified medical researcher, by which point diabetes was on the rise in his home country. In the early 1990s, Yajnik began a study following mothers and their babies in six rural villages near Pune – the Pune Maternal Nutrition Study. The data he started to gather confirmed his hunch that diabetes in India had a very different face from the supposedly classical type 2 diabetes in the textbooks. Yajnik took detailed birth measurements of more than six hundred Indian babies and compared them with a cohort of white Caucasian babies born in Southampton in the UK. Compared to the UK babies, the Indian babies were smaller and lighter. Yet when Yajnik used calipers to measure the thickness of the babies’ skinfolds, he found that the small Pune babies were actually fatter than the Southampton babies – they were surprisingly ‘adipose’, especially around the centre of the body. Yajnik coined the phrase ‘the thin-fat Indian baby’ to describe this phenomenon. Even at birth, these Indian babies had higher rates of pre-diabetes hormones in their bodies than their British equivalents. The babies may have looked thin but their body composition was actually fat.⁶

      We speak of conditions such as heart disease and type 2 diabetes as ‘non-communicable diseases’ or NCDs. You can’t catch an NCD from another person in the way that you would catch a common cold by standing next to someone who is sneezing. But what Yajnik discovered is that babies can actually ‘catch’ a predisposition towards diabetes from their mother in the womb, via the diet she eats. The babies of mothers who were undernourished during pregnancy had ‘fat-preserving tendencies’ – passed on as a survival mechanism.⁷

      It used to be believed that India’s diabetes epidemic was mainly due to ‘thrifty’ genes, endowed over many generations on populations that suffered from patchy and inadequate food supplies. Thanks to decades of malnourishment, these populations were poorly adapted to eat a rich modern diet. Yajnik’s breakthrough was to show that the time frame of maladaptation was much shorter. He speaks not of a thrifty gene but a ‘thrifty phenotype’: the interaction of genes with the environment over a single generation. Depending on the environment in which it develops, a given gene may give rise to different phenotypes. The ‘thin-fat’ baby represents a mismatch of biological environments. These babies grew inside their malnourished mothers with phenotypes for hunger but – thanks to the huge changes in India’s food supply between the 1970s and the 1990s – found themselves eating an unexpectedly plentiful diet.⁸

      When Yajnik first observed the ‘thin-fat’ baby in the 1990s, this was a radically new way of thinking about the interaction of nutrition and health. It took six years for Yajnik to have his first paper on the subject accepted for publication because the mainstream medical establishment was so sceptical of this idea ‘coming from an obscure Indian in an obscure place’, as he puts it. The idea of the ‘thin-fat’ baby only started to gain acceptance when Yajnik published a paper in 2004 revealing that he was a ‘thin-fat’ Indian himself.⁹

      This 2004 paper – which he called the ‘The Y-Y paradox’ – included a now-famous photograph of Yajnik side by side with his friend and colleague John СКАЧАТЬ