Fat is spreading

Obesity epidemic sweeps into developing world

Obesity is spreading to all corners of the globe, researchers warned the meeting of the American Association for the Advancement of Science in Boston. Sedentary lifestyles and fast food are causing previously unaffected populations to fall foul of fat.

“Obesity is no longer confined to Western, industrialized societies,” said anthropologist Marquisa LaVelle of the University of Rhode Island, Providence. Guatemalans in the United States, South Pacific islanders and desert-dwelling Australians are all expanding.

“It puts a burden on the developing world they can ill-afford,” LaVelle warned. Obesity increases the risk of heart disease, diabetes and some cancers. “A decline in world health is inevitable,” she said.

The scale of the epidemic is challenging the view that laziness or genetics are to blame for obesity. Campaigns to promote exercise and a healthy diet have done little to stem obesity’s spread.

LaVelle wants cities and buildings designed to help people lead healthier lives. Urban areas should incorporate playgrounds and footpaths, she suggests. The US Centers for Disease Control and Prevention in Atlanta have begun a project to explore these possibilities.

Obesogenics

The South Pacific may have the world’s highest rates of obesity. In Rarotonga, the capital of the Cook Islands, 52% of men were clinically obese in 1996, compared with only 14% in 1966, Stanley Ulijaszek of the University of Oxford, UK, told the meeting. The figures are worse among skilled professionals.

In rural Papua New Guinea, obesity is on the rise thanks to higher incomes and connections to urban centres. “Modernizing influences are penetrating the remotest places on Earth,” said Ulijaszek.

The global spread of sedentary jobs and energy-rich foods has triggered the epidemic, the researchers agreed. LaVelle labels the lifestyle “obesogenic”.

Some populations with a genetic susceptibility to gaining weight may have been held in check by diet and physical activity until now. But a lifestyle switch can cause dramatic increases in obesity within a generation. “The brakes are taken off,” said Barry Bogin of the University of Michigan in Dearborn.

Mayan children living in the United States are taller and heavier than their counterparts in Guatemala, Dearborn and his colleagues have found. Children whose favourite activity is TV or computer games are at a greater risk of being overweight.