A new report shows that almost one billion people living in developing countries can now be classified as overweight or obese.
The developing world figures are overtaking rates seen in richer countries for the first time, the Future Diets report by the UK's Overseas Development Institute said. The research looked at global data from 1980 to 2008.
"The statistics are quite sensational, it is a tripling of the number of people who are considered overweight and obese in the developing world since 1980," said Steve Wiggins, the report's author. "That takes the number to more than 900 million and that is more than the number of overweight and obese people that we have in the high income countries, which is probably around 570 million, something like that. It is a very rapidly emerging problem and it is now of a very large size."
Two countries with particularly high obesity rates are China and Mexico, where the number of overweight people has almost doubled since 1980.
In South Africa, obesity has risen by a third and the country now has a higher rate than the United Kingdom. North Africa, the Middle East and Latin America all have similar overweight and obesity rates to Europe.
"It is associated with incomes and urbanization and a more sedentary lifestyle," Wiggins said, "so it is those emerging countries which have done the best at raising their incomes. It's the middle income countries, it is the Chinas, it is the Mexicos, which are the countries which are seeing the highest rates of overweight and obesity at the moment," he said.
Alan Dangour, who researches food and nutritional global health at the London School of Hygiene and Tropical Medicine and who was not involved in the report, told the BBC that as developing countries become more urbanized, people’s diets are changing. Sometimes, families living in the same household can have obese and malnourished members at the same time.
"We need to act urgently to deal with the scandal of millions of cases of extreme hunger and under-nutrition in children, but we also need to think what happens if we provide lots of extra calories, containing few vitamins, and encourage excess consumption,” he said.
Processed food, the abundance of sugary drinks and sedentary lifestyles are largely to blame for people piling on the pounds, along with a preference for eating fast food rather than cooking traditional meals at home.
The "Future Diets" report reveals that sugar and sweetener consumption has risen by over a fifth per person globally between 1961 and 2009. The world's top sugar consumers include the U.S., Belgium, the Netherlands, New Zealand and Mexico.
"Taking in a lot more calories in energy dense foods compared to traditional staples, where you are eating say maize and beans, where you get a full stomach fairly early, as opposed to eating cooked pastries with lots of lovely fat and sugar in it and so on," said Wiggins.
The report warns that governments are not doing enough to tackle the growing crisis, partly due to politicians' reluctance to interfere at the dinner table, the powerful farming and food lobbies and a large gap in public awareness as to what constitutes a healthy diet.
Countries singled out for praise in tackling obesity are Denmark and South Korea. In Denmark laws against trans-fatty acids have made Danish McDonalds among the healthiest in the world. Twenty years ago in South Korea the government launched a large-scale public education campaign which has turned around obesity rates.
"A few decades ago the government of Korea said we must encourage our traditional foods, which are low in fats and oils, high in vegetables, high in seafood and so on. And there was a lot of public education, a lot of training and a sense that Korean food is good for you," Wiggins said.
The report predicts that if current rates continue there will be a huge increase in people suffering certain types of cancer, diabetes, strokes and heart attacks, which will put an enormous stress on hospitals.