People who move from villages to cities to work are more likely to end up obese and suffer from diabetes compared to their siblings who remain behind, a large study in India has found.
The study, involving 6,510 participants from north, central and south India, found that half of the migrants had packed on an additional 14 pounds (6-7 kg) by the tenth year of their relocation.
“We have not looked at the extremes, but half the people who migrated put on about 14 lb in weight. This is a dramatic increase. Some people will have put on much more than that,” wrote lead investigator Shah Ebrahim, director of the South Asia Network for Chronic Disease in New Delhi, India.
“The main reasons for weight gain is eating more calories than you need for the energy you burn up in physical activity. We have evidence that migrants tend to eat more fat than rural people, but other nutrients are quite similar.”
“The likelihood is that they just eat more of everything because they have more money to spend on food. We have also found that it is not Western foods that are to blame but just ordinary everyday Indian foods,” he wrote in an e-mail reply to questions from Reuters.
The study, published in PLoS Medicine, surveyed migrant workers in four factories, their siblings who stayed behind in villages, as well as non-migrant urban workers.
Migrant and urban participants were three to four times more likely to be obese than the rural folk, and more than two times more likely to be diabetic, the results showed.
Migrants and urbanites were almost twice more likely to have hypertension and have higher blood sugar than villagers.
Bad lifestyle habits
“Indian cities, are not good places to get physical activity through walking or cycling to work. Reliance on cars is increasing,” Ebrahim said. “Hidden saturated fats, palm oil and sugars are widely used in prepared foods to make them more filling and cheaper to produce.”
Adult-onset diabetes has been linked to risk factors like ageing, an inactive lifestyle, unhealthy diets, smoking, alcohol and obesity. The silent, chronic disease damages the heart, blood vessels, eyes, kidneys and nerves and was responsible for 3.8 million deaths worldwide in 2007.
India carries the highest diabetes burden in the world, with 41 million cases in 2007, projected to hit 70 million by 2025.
While many scientific studies have linked obesity and diabetes to certain genetic mutations, Ebrahim said migration, lifestyle and environmental factors held far more weight.
“The (fat mass and obesity associated gene) in Western populations increases obesity risk by about 3 kg (7 pounds) at most. In India, migration increases weight by double this amount,” he said.
“The dramatic increases in obesity across the United States over two decades are clearly not genetic. American genes have not changed in this short time period. What has changed is the ability of mass marketing of cheap, high-calorie food and the sedentary US lifestyle to reach the majority of the population.”
“Controls on the growing food industry in India and on the costs of saturated, harmful oils and fats would be useful steps to check the obesity epidemic,” he urged.