Gwynne Dyer: Slim chance obesity will last

Being fat is the new normal, but it won't last. The global surge in overweight people is concentrated among lower-income city-dwellers, and some may choose to slim down as they climb further up the income scale. But the real guarantee of a slimmer world, unfortunately, is climate change.

"Obesity is the norm globally, and undernutrition, while still important in a few countries and in [certain groups] in many others, is no longer the dominant disease," Dr Barry Popkin of the University of North Carolina told a conference in Queensland.

Dr Popkin studies "nutrition transition", the changes that accompany the shift from a traditional rural diet to a modern urban diet, and he has concluded that - because of high-speed urbanisation - the fat now outnumber the starving.

We have grown accustomed to Americans who look almost perfectly spherical, and we are seeing more Europeans who seem to aspire to the same goal.

Dr Popkin's point is that this is not caused by moral failure in American and European populations, but to the changes that come with urbanisation: higher incomes, mass-marketing of processed foods, and work patterns that require less physical labour.

His proof is that the rates of obesity in developing countries undergoing rapid urbanisation are rapidly catching up with the levels in the rich countries.

Mexicans of all ages and both sexes are now on average as fat as Americans. In Kuwait, Thailand and Tunisia, 25 to 50 per cent of the population are suffering developed-world levels of obesity.

In some places, specific local factors play a role as well. In much of Africa, for example, fatness in women was traditionally seen as testimony to the wealth and generosity of their husbands.

Research in South Africa has revealed a new, additional factor: the fear that being slim will make people think you have Aids.

But the shift in dietary patterns and the consequent rise in obesity among the urban population affect the great majority of lower and middle-income countries in Asia, the Middle East, Africa and Latin America.

Moreover, this is happening at a much earlier point in the economic and social development of these countries than was the case in the "old rich" countries.

The typical pattern in 19th-century Europe was that the high-income groups put on weight first. Only much later, when cheap fats and sweeteners became generally available to the working class, did the urban poor start to bulk-up as the rich slimmed down.

But this pattern is now kicking in at a point in countries' development where malnutrition is still widespread.

In urban Brazil, for example, the poor are now on average significantly fatter than the rich. Urban adults in China and Indonesia are twice as likely to be obese as rural adults. In the Congo, city-dwellers are six times more likely to be fat.

It's not a pretty picture - a world full of Michelin men and women. The alternative is worse - a world of very hungry people

That alternative, alas, is far more likely by the end of this century. Cheap and plentiful food for the urban masses of a multi-billion-population world is an astonishing achievement, but it is probably in its last few decades.

Most of the world's great fisheries are nearing collapse because of overfishing and pollution. Some, including the Grand Banks, off Newfoundland, have already died.

More worrisome still is the likely impact of global warming on the great agricultural regions that feed most of those billions of people, such as the Chinese river valleys, the American Midwest, and the north Indian plain.

Two years ago, Dr Jyoti Parikh, director of Integrated Research for Action and Development, a New Delhi-based non-governmental organisation, did a detailed study for the World Bank about the probable effects on Indian agriculture of a an average temperature rise of 2C.

She concluded that overall Indian food production would be about 25 per cent less than at present.

The world is probably going to get considerably hotter than that and most of the other great breadbaskets of the world will be similarly affected. Obesity is not our long-term problem.

* Gwynne Dyer is a London-based independent journalist whose articles are published in 45 countries.