THE current Olympic games in London may be all about identifying winners and losers, making more money for big business and enticing even more tourists to Britain, but the world’s most-watched sporting event is also supposed to have a nobler purpose: to get us off the couch and into gyms, parks and swimming pools.

In other words, to encourage people to become more active, to put on their sporting gear and start exercising. But for at least two weeks, many people are likely to be glued to their TV screens watching the games rather than exercising on the treadmill.

In fact, a new study published by the medical journal The Lancet shows that people across the globe could do with a tad more exercise before, during and after the Olympics. Is anyone surprised? Look around and it’s fairly clear that people everywhere appear to be getting fatter. A lot of it is about changes in diets.

But people are also becoming less active, especially in richer nations. Colleagues send e-mails to each other rather than walking across to their offices, even if they are next door. Watching TV is everyone’s favourite pastime and as computers take over our lives, we’re becoming even more sedentary, playing on-screen games rather than real ones outdoors with friends.

My abiding childhood memories are of playing cricket or hide and seek every evening after school. Each time I am in South Asia, the sight of children with cricket bats in their hands makes me smile. But as playgrounds give way to Internet cafes, chubby is becoming the new norm everywhere.

Americans are definitely getting chunkier, a fact which has not gone unnoticed by Michelle Obama. The American First Lady is running a campaign to make Americans eat healthier food. And she has put her two daughters — and already pretty slim husband — on a strict diet.

Mrs Obama has her work cut out though. Visit America and it’s glaringly obvious that the nation’s eating habits are not changing much. Big portions of greasy food and huge tumblers of fizzy drinks appear to be the favourite meal of most Americans.

Europeans are also joining the fat club. Curvy is the new body shape in most European countries. Even the French — much renowned for staying slim while eating foie gras and drinking wine — are putting on weight. I have to say the notion of thin Asians is fading fast. As bread, beer and meat enter the Asian diet, replacing rice, lentils and fish, Asians are piling on extra weight.

But it’s not only about food. The much-quoted Lancet study says the problem is that people just don’t get enough exercise. The study measured global physical activity levels for adults — defined as those over 15 — from 122 countries. Inactivity was defined as a failure to meet any of the following criteria: 30 minutes of moderate activity five times a week, 20 minutes of vigorous activity three times a week or some combination of the two.

Overall, researchers found that almost a third of adults are more couch-bound than is desirable. They also discovered that physical inactivity increased both with age and income: rich countries were found to be more sedentary than poor ones. And high levels of inactivity among women corresponded to those nations that have strict barriers to female employment.

The growing sedentary lifestyle has real health consequences. Physical inactivity is to blame for one out of 10 deaths globally, about the same rate as deaths caused by smoking.

As Pedro Hallal, the lead author of the study, puts it, “the human body has evolved in such a way that most of its systems do not develop and function in an optimum way unless stimulated by frequent physical activity.”

Of the 122 countries which were surveyed, The Lancet found that the world’s most inactive nations are Malta, Swaziland and Saudi Arabia. Described in newspapers as the ‘most slothful nation’, 72 per cent of adults in Malta were found to be getting too little exercise. Swaziland and Saudi Arabia were close behind, with 69 per cent.

People in Bangladesh, by contrast, move around a great deal, with just five per cent of adults failing to get enough exercise.

Other active winners include Mozambique with 7.1 per cent inactivity, Benin with 9.1 per cent inactivity, Mongolia at 9.4 per cent and Cambodia at 11.2 per cent.

In these active societies most citizens get enough exercise to prevent heart disease, diabetes and certain cancers.

Across the world women tend to get less exercise — 34 per cent are inactive, compared with 28 per cent of men. However, women in Russia, Croatia, Luxembourg, Greece and Iraq (to name a few) move more than their male counterparts. Women’s inactivity is not a surprise, especially in conservative Islamic societies where female sports are discouraged. But women in poorer Muslim countries do move around — working at home, walking to shops for instance — much more than in richer countries.

Personally, I would like to be much more active than I am at the moment. But still I make an effort. I may drive to work but my office sits on a hill in a park, so there is a nice five-minute walk uphill every morning and sometimes even two or three times a day. A friend once told me to take the stairs everywhere, whenever possible, rather than lifts and escalators so I try and follow his advice.

I go to the gym on weekends, practice yoga and take dance classes. But the truth is it’s not enough. According to The Lancet, I should be doing much more.

The study is right. We should all be moving around more and exercising as much as we can. However, surely we should also be eating less and better?

The writer is Dawn’s correspondent in Brussels.