Obesity: Who is to blame?

Around 300m people around the world are obese and that figure is predicted to rise sharply in the years ahead. Who, if anyone, is to blame?

This week, the world's largest fast food chain announced plans to introduce healthier menus in many of its restaurants.

Out go super-sized fries and drinks and in come chicken salads, yoghurts and chopped fruit.

But what should have been a public relations triumph for McDonald's quickly turned sour when it emerged that its salads may contain more fat than its burgers.

The subsequent headlines put the company back in the firing line over obesity.

The corporate giant, like many others in the food industry, has been accused of contributing to rising rates of obesity in many western countries, something it strongly denies.

"The obesity debate is a very complex one and is widely recognised to include considerations not just of diet but also individual responsibility and increasingly sedentary lifestyles," the company said in a statement.

The courts appear to agree. Last year, a group of New York teenagers tried to take McDonald's to court claiming its food was addictive and had made them obese.

The case was quickly dismissed. The presiding judge Robert Sweet said: "It's not the place of the law to protect them against their own excesses."

Certainly, there has been a growing trend, in the United States at least, towards shifting blame away from the fast food sector.

'Cheeseburger Bill'

It's a view shared by many American politicians. This week, the US House of Representatives voted in favour of legislation which would make it illegal for anyone to sue fast food companies claiming they made them obese.

The so-called Cheeseburger Bill needs the backing of the US Senate if it is to become law, but reports suggest it already has the support of the White House.

Nevertheless, many scientists insist fast food is contributing to rising rates of obesity.

Last year, researchers at Princeton University published a study which suggested fast food may be as addictive as heroin.

They said rats fed a diet of high-sugar, high-fat foods suffered withdrawal symptoms when they went without.

In October, British scientists warned that the human body simply wasn't designed to eat the high-calorie food being sold in fast food outlets and supermarkets.

"The systems regulating human appetite have evolved for the low-energy diet still being consumed in rural areas of the developing world where obesity is almost non-existent," said Professor Andrew Prentice of the London School of Hygiene and Tropical Medicine.

"Our bodies were never designed to cope with the very energy-dense foods consumed in the West and this is contributing to a major rise in obesity."