By Michael Regnier

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A warm egg, white shell almost translucent, plops into the wire mesh gutter and rolls forward. There is no let-up in the clucking din of the 16,000 other chickens in cages that stretch to the far end of the shed. They won’t survive more than a couple of years here, but their shit will be shovelled up for fertiliser and their eggs sold on for a few rupees each.

The concrete shed stands between two rice fields, patches of green in the otherwise brown, dusty landscape of this part of central southern India. The farm belongs to Narasimha Reddy, who also grows oil palms and a traditional cereal called jowar. It is hard work but he says he is satisfied with his lot. Most of his neighbours have sold their land, which Reddy claims has made them less happy. He also says they are less healthy because they now don’t work as hard and have changed from jowar to rice in their diet.

Reddy strives to be more traditional. He sticks to the same diet his elderly parents have eaten all their lives, and unlike many neighbouring families, he and his three brothers have all stayed in the village. He envisages his children living out their lives here as well. It is a rare vision of the future. Across India, so many people are leaving the land in favour of the rapidly growing towns and cities that the rural population is predicted to peak around 900 million before starting to shrink in 2025. Already, this trend is bringing profound economic and social changes to individuals, families and the nation as a whole. It is changing the way people live. It may also change the way they die.

As more Indians adopt more urban lives, chronic conditions like diabetes, obesity and heart disease are on the rise, replacing malnutrition and infectious diseases as the country’s most urgent health worries. Reddy doesn’t want to risk his family’s health. He has decided that being healthy and poor is better than taking their chances in the modern, more developed, more open India.

But they are not immune in the familiar confines of the village, either. The same chronic diseases are rising in rural India too, albeit more slowly than in its cities. So what really lies behind this national trend, threatening the health of hundreds of millions of people in villages and cities alike? And is Reddy’s strategy of keeping his family locked in a traditional life of jowar and agricultural labour the answer, or is he spurning potential new opportunities in vain?

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Sanjay Kinra is an urbane doctor with a lively, witty intelligence – good company as we drive out to Reddy’s village. It is one of 29 villages between 50 and 100 km south of Hyderabad, India’s fourth-largest city, that Kinra believes could unlock some answers about the rise in chronic, non-communicable diseases. A study of nutrition took place in the area some 25 years ago and Kinra, a paediatrician and public health researcher, has since recruited thousands of people in the 29 villages to revisit that long-forgotten study. He now wants to follow the participants’ long-term health in order to understand what factors have the most influence on their wellbeing.

Two doors up from Reddy’s house just off the village square, Kinra and I meet Mahmad Babumia, a retired police official. He wears a neat white beard on his chin and a neat white shirt with a ballpoint pen in the breast pocket. Life in the village was bad 30 years ago, he reports. The buildings were all kachcha – mud huts – and everyone laboured on the land but there wasn’t enough to eat, even with the government providing subsidised rice at 2 rupees a kilo.

A welfare scheme, initiated across India in the 1970s, aimed to supplement the diets of pregnant women, breastfeeding mothers and children under six. In 1987, researchers from the National Institute of Nutrition in Hyderabad identified 29 nearby villages where they would be able to assess how well this programme was working. When they started the Hyderabad Nutrition Trial, 15 of the villages were receiving free food for mothers and children; the other 14 were still waiting to start the programme, so acted as controls in the experiment. Over the next three years, researchers recorded the weight of babies born in all the villages to see what difference, if any, the extra food was making. One of the 4,300 babies born during the trial was Babumia’s son Mustak.

Overall, the results suggested that babies like Mustak, born in villages with the programme, were on average 60 to 80 grams heavier than those born in villages without it. And that was that. The findings were not widely disseminated and the study seemed destined for obscurity – until 2003, when Sanjay Kinra dusted it off and saw untapped potential.

Having trained as a doctor in his hometown of Delhi, Kinra had then moved to the UK to practise medicine. He specialised in paediatrics but developed parallel interests in environmental health and epidemiology. When he began to wonder if there was a tangible link between a child’s diet and their risk of heart disease in adulthood, he looked for a PhD research project that would let him investigate further. He got wind of an old study that had tested the effect of supplementing the nutrition of children in some rural Indian villages. Perfect, thought Kinra: he could go back to these people and see whether differences in the children’s diet had produced any differences in health as they had grown up.

There was a problem, though. When he got hold of the old trial records, they were incomplete and existed only on paper and outdated computer disks. Even when he was able to go through them, Kinra realised he didn’t have the names of the children born during the trial, only their dates of birth.

Undaunted, he went to each of the 29 villages and tracked down as many of the original trial participants as he could. The mothers were relatively easy to find, but it’s rare for rural parents to know their child’s date of birth. By comparing lunar calendar dates and significant local events with the dates of birth recorded by the researchers 15 years before, he managed to identify about half of the children from the original trial. Together with parents and siblings, this gave Kinra a cohort of 7,000 people with whom he could do a follow-up study.

However, it soon became clear to him that there was much more to be gained here: if he could continue to follow these children over many years, he might be able to find associations between childhood nutrition, lifestyle, environment and other factors and the risk of developing chronic health conditions.

The children were already teenagers by this time, of course. And in their lifetime, conditions in the 29 villages had been transformed – not by government welfare schemes, but by India’s rampant economy.

Just a few kilometres north-west of Reddy’s farm lies Ramoji Film City, a sprawling gated compound where the Hyderabad film industry rolls out enough movies each year to rival Bollywood. Busloads of workers are disgorged onto the 1,700-acre site each day to make films on elaborate sets and sound stages. The morning we drove through on our way to the villages, I saw a mock-up of Chennai airport with a biplane parked in front of it, a stationary steam locomotive ready to play its part, and a side street with no main road to turn off but every type of urban housing you could wish for. All in the middle of the semi-arid, all-but-deserted countryside outside Hyderabad.

This ‘dreamscape’ was the vision of Ramoji Rao, a wealthy entrepreneur and film producer, and he was able to realise it in the boom times of the mid-1990s. When he opened Film City in 1996, everything changed for the nearby villages. Their land suddenly became worth something – developers thought that Hyderabad’s urban sprawl would be inevitably drawn their way.

Unlike Reddy, Mahmad Babumia was keen to cash in. Three-quarters of the families in their village have since sold up, although their former fields sit brown, barren and undeveloped, still waiting for the anticipated demand to materialise. Babumia used the windfall to buy a concrete house in the village; others built their own, used the money to move away, or took the opportunity to stop breaking their backs in the fields. Many found new jobs in Film City: Babumia’s five sons all work there now, handling the cameras and lights. They are earning cash, which they spend in the nearby town, occasionally going shopping in Hyderabad itself. Two of them have moved out and live in the town, closer to schools, healthcare and shops superior to anything the village has to offer.

Kinra asks him why he thinks he got diabetes and high blood pressure. Babumia answers that earlier generations didn’t get these conditions. He says his father was healthier at his age than he is now because the quality of food has deteriorated even as quantity has increased. “The food has no power,” he grumbles. “The younger generation eat less vegetables, just white rice, and they get sick younger.”

But this is inconsistent. Although Babumia remembers his parents’ generation living to 100 compared with 60 or 70 today, his father died during the food shortages, while Kinra knows that life expectancy in India 20 years ago was just 46.

As for future generations, Babumia’s son Mustak, one of the original Hyderabad Nutrition Trial babies, still lives in the village – for now. But it’s when young men get married and start a family that they think about moving, so in a few years Mustak may well decide to join his two brothers who are already in the town. There are undoubtedly better opportunities for their children there, but would there also be a long-term cost?

Your health is inextricably linked to where you live. Changing where you live therefore influences your health. This phenomenon has been studied over decades in people who migrate between countries, radically switching living conditions in a matter of weeks or even days.

You don’t have to change country to change environment, though. Across the globe, internal migrants outnumber international migrants four to one. Either way, most people who migrate go from a village or town to a bigger town or city. And although internal migration usually involves a less arduous process than crossing international borders, the change in environment can be just as rapid and profound, and it can also affect migrants’ mental and physical health – for better or worse.

According to 20th-century wisdom, people who migrated were generally healthier than those they left behind. They had to be fit to take on the rigours of travel and setting up a new life from scratch. When they arrived at their destination, migrants were expected to be less healthy than their new neighbours – city dwellers would, in theory, have the advantages of better access to healthcare, a more varied diet, and cleaner surroundings. However, some research showed that migrants tended to start out healthier than existing city dwellers, who had typically grown up with the city’s stresses, fast food and fattier, more sugary diets, alcohol, and more sedentary routines. The advantage didn’t last. As ‘healthy migrants’ adopted urban lifestyles, they became increasingly prone to metabolic disorders: chronic conditions like obesity and diabetes that, in turn, raised the risk of heart disease.

Around the same time that he was tracking down the children of the Hyderabad Nutrition Trial, Sanjay Kinra started working on another project. It was to test whether internal migrants in India experienced the same ‘healthy migrant effect’ that had been observed in international migrants, such as Japanese migrants to the USA. A migrant himself, Kinra was now working for another man who knew a thing or two about the process.

Shah Ebrahim was born and raised in Yorkshire but has deep roots in other parts of the world, too. His grandfather migrated from India to South Africa at the end of the 19th century, then his father moved to the UK in the 1940s to escape apartheid and qualify as a doctor. Ebrahim followed his father into the medical profession but became increasingly interested in epidemiology and public health. Perhaps it was inevitable, given his family history, that he would eventually decide to investigate the effects of migration on health.

“Migration is the story of modern times,” says Ebrahim. “Migration and encroachment, the absorption of small villages into urban sprawls and the clearing of habitat for roads and housing. But the patterns of human living require habitats to sustain them.”

In 1984, 5 per cent of adults in India’s towns and cities had diabetes. By 2004, when Ebrahim started the Indian Migration Study, this had trebled to 15 per cent. It was also rising in the villages but lagged behind at around 6 per cent. Obesity and high blood pressure were on similar trajectories. If those trends proved to be linked to India’s inexorable urbanisation, public health responses could be tailored to reduce the impact of these conditions on people’s quality of life and life expectancy.

The study was designed around four factories in cities along a rough north–south axis of India: Lucknow, Nagpur, Hyderabad and Bangalore. Rather than just compare people in rural and urban areas, the researchers wanted to look at migrant workers who had moved from one environment to the other. But they needed control groups. In each factory, therefore, they recruited employees who had moved from a rural village to come and work there and who, crucially, also had a brother or sister still living in their home village. The siblings were ‘negative controls’, accounting for factors associated with their origin. To account for destination factors, the researchers recruited other factory employees who were born and raised in the city, and some of their siblings too, to act as ‘positive controls’.

What they couldn’t entirely account for was selection. “You have to be fairly fit to migrate,” says Ebrahim. “Or stupid.” Whatever differentiated the siblings who moved from those who stayed behind – be it fitness or stupidity, motivation or drive, optimism or a risk-taking personality – was impossible to measure. However, although unknown selection factors may conceivably have had some influence over their participants’ health, the researchers were satisfied that their study, with 6,500 participants, would yield robust information about the effects of migration – in particular, the effects of moving from a rural environment to an urban one.

Hyderabad was founded in the 16th century. It is still known as the City of Pearls, despite recent attempts to rebrand it ‘Cyber-abad’, but is more famous today for its biryanis and its traffic. The centre is a constant crush of cars, lorries, auto rickshaws, motorbikes, bicycles, carts, cows and pedestrians, all weaving around each other, continually sounding their horns, congesting but seldom coming to a complete stop. Constant noise and motion.

The city is home to 8 million people today. As it has grown in population, so it has pushed out its boundaries, swallowing outlying villages and making them urban. To the west, the flourishing Financial District looms over a community that still looks rural: cows wander by, hens peck in the dirt at the roadside. But, whether they liked it or not, the people here had to adapt as the city engulfed them. They sold their farms to developers hungry for suddenly prime real estate, and found new occupations that yielded cash instead of crops.

New people have moved in to set up shops and small businesses. The better-educated commute to work for the big Indian corporates and multinational giants like Microsoft who now have offices here. They can eat lunch at a new branch of Domino’s Pizza, if they want. Casual labourers – all migrant workers – spend their nights in blue and brown tents or makeshift shacks they have built from corrugated iron, and their days building glass and steel edifices. A village goat grazes nonchalantly in front of what will soon be a Holiday Inn Express. This is the global village, and it has been urbanised.

In Aravind Adiga’s novel The White Tiger, the main character compares the plight of 99.9 per cent of Indians to that of chickens caged in the ‘Rooster Coop’ in an Old Delhi marketplace: “They know they’re next. Yet they do not rebel. They do not try to get out of the coop.” The people in this ‘village’ within the city have been released from traditional rural subsistence and forced to fend for themselves in a modern, free-range, urban economy instead. Of course, it may turn out to be just another type of poverty trap.

Like most cities, Hyderabad is a patchwork of communities that bear witness to its history. Rural people would travel great distances to seek their fortune in the city, but if they couldn’t find a foothold there, they would settle at its margins. Relatives and former neighbours from the same village would follow suit, and set up in the same place. Unsanctioned by the city authorities, and therefore lacking basic services like water and sanitation, these informal communities sometimes survived the city’s expanding sprawl, and would become its slums.

A city slum can be many things – a community, a poverty trap, a potential escape route for the next generation.

Other settlers were made to feel more welcome. When Bharat Heavy Electricals Limited (BHEL) built a factory at the western edge of Hyderabad, the company was able to provide more than just a job for its workers – it established a whole new suburb. The BHEL township has housing, but also parks, shops, an athletics stadium, schools, colleges and a general hospital that provides free healthcare to employees and their children. It was the perfect site to study the health of migrant factory workers, and so the Indian Migration Study team set up a clinic in the BHEL hospital to assess their Hyderabad participants.

The overall findings, published in 2010, showed that the urban environment was indeed a significant factor in the development of serious chronic health conditions. Within a few years of moving to Hyderabad or the other cities in the study, migrants’ levels of obesity, high blood pressure and diabetes were closer to those of lifelong city dwellers than their rural siblings. Migrant men were more likely than women to have an increase in blood pressure and their risk of heart disease was higher, too. Women were more likely to have put on weight. Whatever the gender difference, internal migrants quickly acquired higher risks of heart disease and related conditions as they adopted the city lifestyle.

As the nature of migration and mobility in India develops and changes, the question becomes whether the modern urban habitat will do more harm than good in the long run.

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High-school physics teacher Vijaya Jyothi lives in a quiet middle-class suburb of Hyderabad. Originally from one of the 29 villages in Sanjay Kinra’s study, she moved with her husband and two children, first to a nearby town in 2003 and then to Hyderabad in 2011. Living in the city means running water (albeit on alternate days), a reliable electricity supply (daily power cuts of two hours in summer and four hours in winter, compared to 12-hour outages in the village), better education for their children, now aged 13 and 11, and better access to healthcare.

Like many rural-to-urban migrants, however, Jyothi says the village was a healthier place to live because there was less pollution. The family’s diet, too, changed when they moved here: no more plain cereal rotis for breakfast but rich dosas (stuffed rice and lentil pancakes), and while there is a greater variety of vegetables available than in the village, where they could only really eat what they grew themselves, there is also more fast food. They are less physically active than when they cycled to work in the family fruit orchards. They even have a servant now who does the cleaning, freeing up more time for Jyothi to spend with the children.

Life is indisputably better for the family, but they have begun to feel their health deteriorating.

Many people lament current trends towards eating more white rice, inactive lifestyles and the lack of clean air in the cities, but it seems harder to do anything to resist them. Jyothi is trying: she has decided to switch back to a more traditional breakfast, and has started doing yoga and taking regular morning walks.

Despite their conviction that village life is healthier, few rural-to-urban migrants entertain any thoughts of moving back. Health is still a price they are willing to pay for a better life in the city.

The 29 villages in Kinra’s study are not typical of rural India. They lie close to a major city and got the unique boost of Film City on their doorstep. It opened up new options, though not everyone has elected to take advantage. But despite their unusual circumstances, these villages might just be a microcosm of India’s future. The largest village has already grown into a bustling town, attracting people from the other villages, which are themselves developing. It might take longer in other parts of the country, but India’s villages are all somewhere along this path.

At the same time, people are more mobile than ever before – young men give rides to family and friends on their motorbikes, while others use the (admittedly capricious) local bus services to travel between villages, towns and the city. It is much easier to find work beyond your village and easier, too, to find a home and a job in the town before making the move there. The result is that more people have more of a say about where and how they live.

By following the health of people in 29 relatively rapidly developing villages, Kinra will see how our health is affected by changing environment, whether through migration, urbanisation or even, by extension, phenomena like climate change. To generate strong evidence, though, he is not content with a sample of 7,000 villagers – he wants them all.

Today, the project is run from the National Institute of Nutrition, home of the original Hyderabad Nutrition Trial – Kinra has renamed it the Andhra Pradesh Children and Parents Study (APCAPS). The team is based in house A7 on the institute’s leafy suburban campus. Almost every room in the building has stacks of files teetering on shelves, tables, filing cabinets – anywhere there is a scrap of space. The information will eventually be recorded on tablets, but for now the database is still paper-based. Among the records are the files belonging to science teacher Vijaya Jyothi, Mahmad Babumia and his five sons, and the farmer Narasimha Reddy.

From the first follow-up in 2003, a second round in 2009 and a third in 2010, the team has gathered information about all the participants’ diets, physical activities and lifestyles, as well as measuring body size and composition, lung function, blood pressure and the levels of various proteins in the blood. Kinra and his team could now wait and see what patterns emerge as some of these people start to develop chronic health conditions. But instead, they are adding to their data. They have installed air quality monitors and mapped the location and use of every building in the villages, and are recording the price of food in all the shops. All this in preparation for extending the study to every inhabitant, a potential group of 60,000 people in all.

Kinra describes APCAPS as a “natural experiment”. Unlike the Indian Migration Study, it will follow changes in health before, during and after changes occur to people’s environments. He believes it will reveal the reasons why some people develop chronic diseases and associated risk factors, such as smoking, high blood pressure and over- and underweight, and others don’t.

The twin trends of urban development and increasing mobility are likely to be playing a role, but not everyone in the same situation develops diabetes, for example, so understanding the balance of factors is essential. Because the villages will not urbanise all at once, but with different elements of urban life – changes in diet, air quality, physical activity and so on – developing at different times, the study should be able to identify which factors are most important. Ultimately, Kinra hopes the findings will help to reduce the negative effects of modern living as the next generation of Indians seek better lives.

“It is not a choice between urbanising or not,” he says. “It is a question of how to go about it so as to minimise the health impact on people.”

His parents named him Sainath but he prefers to be called Dileep. Aged 16, he lives in the very smallest of the 29 villages, home to just 500 or so people. The family home is set back from the main road that runs between rows of concrete houses painted with pale washes of eggshell blue. A line of electricity pylons runs alongside the road but there is no running water here. In patches of ruddy soil around the house, Dileep’s mother, a seamstress, grows onions, tomatoes, papaya, custard apples, chilli peppers and curry leaves, and each night his father and the other daily labourers bring back food crops from the fields. They say they are healthier and happier here than they could be in the city, but Dileep will almost certainly forsake village life in order to achieve his ambition of becoming an accountant.

Dileep goes to a school on the outskirts of Hyderabad. The urban environment holds many temptations for a young man beyond education and future employment – street stalls selling Chinese-style fried rice, internet shops to check Facebook, tea shops with their ubiquitous speak-your-weight machines. For 1 rupee, you can find out your weight and your fortune while you wait for a glass of coffee, chai tea or hot almond milk, all invariably served with heaps of added sugar. When Kinra asks him about his diet, Dileep confesses a fondness for egg puffs from the baker’s in town – but he says he doesn’t indulge very often. It will become harder to resist if he lives there, gets behind an accountant’s desk and starts earning a disposable income.

Not everyone will move. We each have our own reasons for staying or going; our own balance of vulnerability, resilience and response; our own story. APCAPS aims to help reveal the physiological consequences of migration and urbanisation, so that we can make more informed, more confident decisions about where to live. If Dileep’s generation can take more accurate account of how their choice of home will affect them, India could be transformed into a country where health no longer has to be sacrificed for a better life.

The Wellcome Trust, Mosaic's publisher, funded the Indian Migration Study and has also funded elements of the APCAPS project.

This article first appeared on Mosaic and is republished here under a Creative Commons licence.