Gluttony (overeating) - not laziness (exercise) - to blame for obesity

• 11:15 19 August 2008
• NewScientist.com news service
• Tamsin Osborne

Greed - not sloth - might be responsible for the obesity epidemic, according to research showing that we're doing just as much physical activity as we were in the early 1980s.

An increasingly inactive lifestyle is often blamed for the soaring obesity rates in the developed world, but few studies have measured whether lifestyle changes have decreased the amount of energy we burn.

To address this, John Speakman of the University of Aberdeen, UK, and Klaas Westerterp of Maastricht University in the Netherlands looked at the amount of energy used through physical activity over the past 25 years in 393 people from across the US and 366 from Maastricht.

In these subjects, energy expenditure has been measured since 1982 using a technique called the "doubly labelled water method", which measures the throughput of water labelled with isotopes of hydrogen and oxygen. By comparing the daily energy expenditure in the early 1980s with current data, the researchers showed that there has been no significant decline in the energy the people studied burned through physical activity.

The obesity epidemic had already started by 1982, but Speakman argues that people have always been fairly inactive during the evenings, and that although activities such as watching TV and playing computer games might be relatively new, they have not affected overall energy expenditure.

"Prior to widespread TV ownership we probably spent this time listening to the radio, before that reading, and before electrical lights were discovered we would have been asleep," he says.

If we are not less active, then we must be eating more food, suggesting that trying to increase our energy expenditure through physical activity may not be the best way of tackling obesity.

"If we want to reverse the obesity epidemic it would be much better to focus on trying to decrease caloric intake," says Speakman.

But Paul Zimmet of Monash University in Victoria, Australia, warns that

a complex problem like obesity requires a complex solution. "Addressing the current obesity epidemic requires an integrated approach over and above modifying energy intake," he says.

Journal reference: International Journal of Obesity (DOI:10.1038/ijo.2008.74)

Nature - full text.

Beating the bulge (again)

Beating the bulge (again)

By Nick Triggle Last Updated: Wednesday, 23 January 2008 Health reporter, BBC News

Projects to tackle obesity have been scrapped

Everyone is agreed that obesity is one of the greatest challenges facing the country.

Nearly a quarter of adults are obese after rates rose by 50% in the last decade.

The increases among children have been even worse.

The government has recognised that the problem needs to be tackled by drawing up an obesity strategy, which will be published on Wednesday.

But this is far from the first time ministers have tried to tackle the nation's expanding waistlines. So what has gone wrong?

Back in 1992, the Tories published a white paper, Health of the Nation, which set a number of targets to tackle obesity.

These were subsequently dropped by Labour after it came into power in 1997.

But the Blair government was back worrying about eating habits with its own public health white paper in 2004.

Crackdown

Choosing Health set out a range of measures, including food labelling, a crackdown on TV junk food advertising and school-based campaigns to get children exercising and eating healthily.

But the key problem, according to public health experts who warmly welcomed the proposals at the time, was that the government has not kept promises over money.

The 2004 white paper said public health chiefs would get an extra £300m over the following two years.

A snapshot survey by the Faculty of Public Health, which represents public health specialists, has shown that as little as 40% of this money actually reached the front line.

Responding to the challenge requires the whole of government to work together Dr Tim Crayford, of the Association of Directors of Public Health

Professor Chris Drinkwater, a public health expert at the NHS Alliance, which represents health professionals working outside hospitals, said: "The problem is that the funds were not ring-fenced and became a soft option when the NHS was having problems with deficits."

The result has been that much of what was envisaged at the time has not materialised.

Promised improvements to the cycle network have not been carried out, while the sale of school playing fields has continued.

The effect is that the government will almost certainly miss its target to halt the year-on-year rise in childhood obesity by 2010.

In fact, ministers are facing an uphill struggle to even encourage the public to adopt healthier lifestyles.

Improvement

Despite gradual improvements in recent years, over two thirds of adults are not doing the recommended five 30-minute sessions of exercise a week.

Meanwhile, the five-a-day fruit and vegetable intake is more like three-a-day for most.

And even where targets were set and hit, in the case of health trainers, it has required outside investment.

The aim was to appoint 1,200 of the lifestyle coaches by March last year, but figures show nearly half of them have been employed by the army and prison service.

Professor Alan Maryon-Davis, president of the Faculty of Public Health, said the problems are being worsened by cuts in the number of public health specialists.

In the last four years the number of consultant and director posts in the NHS has been reduced by over a quarter, he said.

"These are the people who would be co-ordinating local approaches - the schools sports programmes, the organised walks.

"It is things such as this that are essential to tackling obesity, but without the public health specialists in place they end up being cut."

Dr Tim Crayford, president of the Association of Directors of Public Health, agrees. "Responding to the challenge requires the whole of government to work together. It involves transport, education and health. But unfortunately it has been losing out to other priorities."