As poorer nations develop economically, they also seem to develop obesity. An international study has found that rising rates of obesity and diabetes are linked to the level of TV, car and computer ownership.

The negative health effects of these symbols of economic progress have long been seen in the wealthier nations, where 83% of the people own all three devices, and obesity is common. The study hints that poorer nations, where only 4% of the people own all three devices, will likely soon be facing their own obesity crisis as their economies grow and they become wealthier.

People in low income countries who owned all three devices showed a 31% decrease in physical activity and a 21% increase in time spent sitting compared with those owning none of the devices.

People who owned all three devices in lower income nations had an obesity rate more than quadruple that of people who owned none of the devices. Type 2 diabetes also more than doubled among people who owned all three devices compared to non-owners.

The most obvious reason for this? Inactivity. People in low income countries who owned all three devices showed a 31% decrease in physical activity, a 21% increase in time spent sitting, and an increase of nearly four inches in waist circumference, compared with those owning none of the devices.

Among the three devices, owning a television had the strongest association with obesity.

Most studies on the role of TVs, cars and other consumer goods on health have been done in the wealthier nations. So even though it's been predicted that rapid development and industrialization of poorer countries will lead to increases in obesity and diabetes, there's been little solid evidence of this until now.

Not just a report of doom and gloom, the findings emphasize the importance of limiting TV, car and computer use; the research also supports decreasing total time spent sitting, as part of the recipe for good health, as well as making sure you stay physically active.

Canadian researchers reviewed data on more than 150,000 adults in over 100,000 households in 17 different countries. Participants were asked about physical activity, sitting time and diet, and whether they owned a TV, computer or car, or had diabetes. Their height and weight were also measured.

Various countries were classified according to their economic profile:

High Income: Canada, Sweden, United Arab Emirates
Upper Middle Income: Argentina, Brazil, Chile, Malaysia, Poland, South Africa, Turkey
Lower Middle Income: China, Columbia, Iran
Low Income: Bangladesh, India, Pakistan, Zimbabwe

While the researchers found a strong relationship between owning TVs, cars and computers and obesity/diabetes in poorer countries such as India and Pakistan, as countries became wealthier the connection tended to diminish.

For example, the relationship between car, computer and television ownership and obesity was moderate in middle income countries like Poland and Colombia — detectable, but not as strong as in the poorer countries. And it was not at all apparent for people in wealthier countries. The authors suspect this is because the negative impact of these devices on health in the wealthier countries had already occurred a long time ago.

Aside from predicting what may be in store for less developed countries as their stock of consumer goods increases, perhaps the study suggests that the road to a healthier life starts with abandoning your TV.

The study appears in the Canadian Medical Association Journal.