The extent of the world's obesity epidemic has been outlined in a report by Britain's Overseas Development Institute (ODI) that puts the number of overweight and obese adults in developing countries at over 900 million.
According to the report, overweight and obesity rates have almost doubled since 1980 in China and Mexico, and risen by a third in South Africa.
"The growing rates of overweight and obesity in developing countries are alarming,"said the report's author, ODI research fellow Steve Wiggins.
"Future Diets", an analysis of public data about what the world eats, says there are almost twice as many obese people in poor countries as in rich ones. In 2008, the figures were 904 million in developing countries, where most of the world's people live, compared with 557 million in industrialised nations.
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 influence of farming and food lobbies and a large gap in public awareness of what constitutes a healthy diet.
"The evidence is well established: obesity, together with the excessive consumption of fat and salt, is linked to the rising global incidence of non-communicable diseases, including some cancers, diabetes, heart disease and stroke," says the report.
Factors behind the increase in obesity include rising incomes and urbanisation, which tend to lead to diets rich in animal produce, fat, salt and sugar; and the various influences of globalisation, among them advertising and the media, on diets. But the report cautions against jumping to conclusions that national diets are converging on a single international norm.
In China, for example, diets, are proportionally richer in animal products and vegetables than in the 1960s, but sugar consumption remains low. In contrast, Thailand has experienced an increase in the per-head consumption of starchy roots and pulses as well as fruit, which Thais consume more than animal products.
Some governments have managed to change diets for the better. South Korea has increased fruit and vegetable consumption through a publicity, social marketing and education campaign, including training of women to prepare traditional low-fat, high-vegetable meals. Denmark banned trans-fats, which have made its McDonald's among the healthiest in the world.