Hunter gatherer clue to obesity

abercrombie saleThe idea that exercise is more important than diet in the fight against obesity has been contradicted by new research.A study of the Hadza tribe, who still exist as hunter gatherers, suggests the amount of calories we need is a fixed human characteristic.This suggests Westerners are growing obese through over-eating rather than having inactive lifestyles, say scientists.One in 10 people will be obese by 2015.And, nearly one in three of the worldwide population is expected to be overweight, according to figures from the World Health Organization.The Western lifestyle is thought to be largely to blame for the obesity "epidemic".Various factors are involved, including processed foods high in sugar and fat, large portion sizes, and a sedentary lifestyle where cars and machines do most of the daily physical work.The relative balance of overeating to lack of exercise is a matter of debate, however.Some experts have proposed that our need for calories has dropped drastically since the industrial revolution, and this is a bigger risk factor for obesity than changes in diet.A study published in the journal tested the theory, by looking at energy expenditure in the Hadza tribe of Tanzania.The Hadza people, who still live as hunter gatherers, were used as a model of the ancient human lifestyle.Members of the 1,000-strong population hunt animals and forage for berries, roots and fruit on foot, using bows, small axes, and digging sticks. They don't use modern tools or guns.A team of scientists from the US, Tanzania and the UK, measured energy expenditure in 30 Hadza men and women aged between 18 and 75.

abercrombie sale ukThey found physical activity levels were much higher in the Hadza men and women, but when corrected for size and weight, their metabolic rate was no different to that of Westerners.Diverse lifestyles Dr Herman Pontzer of the department of anthropology at Hunter College, New York, said everyone had assumed that hunter gatherers would burn hundreds more calories a day than adults in the US and Europe.The data came as a surprise, he said, highlighting the complexity of energy expenditure. But he stressed that physical exercise is nonetheless important for maintaining good health. "This to me says that the big reason that Westerners are getting fat is because we eat too much - it's not because we exercise too little," said Dr Pontzer."Being active is really important to your health but it won't keep you thin - we need to eat less to do that."Daily energy expenditure might be an evolved trait that has been shaped by evolution and is common among all people and not some simple reflection of our diverse lifestyles." Sugar is as damaging and addictive as alcohol or tobacco and should be regulated, claim US health experts.According to a University of California team, new policies such as taxes are needed to control soaring consumption of sugar and sweeteners. Prof Robert Lustig argues in the journal for major shifts in public policy. Industry body the Food and Drink Federation said "demonising" food was unhelpful.Several countries are imposing taxes on unhealthy food; Denmark and Hungary have a tax on saturated fat, while France has approved a tax on soft drinks.

abercrombie and fitch ukNow, researchers in the US are proposing similar policies for added sugar and sweeteners, amid concern about the amount of sugar in the diet. The consumption of sugar has tripled worldwide over the past 50 years, with links to obesity, high blood pressure and diabetes.In a comment in the journal Nature, Prof Lustig, a leading child obesity expert, says governments need to consider major shifts in policy, such as taxes, limiting sales of sweet food and drinks during school hours, or even stopping children from buying them below a certain age. The professor of paediatrics at the University of California, San Francisco, told the BBC: "It [sugar] meets all the criteria for societal intervention that alcohol and tobacco meet."The researchers acknowledge that they face "an uphill political battle against a powerful sugar lobby".But they write in Nature, that "with enough clamour for change, tectonic shifts in policy become possible"."Take, for instance bans on smoking in public places and the use of designated drivers, not to mention airbags in cars and condom dispensers in public bathrooms."These simple measures - which have all been on the battleground of American politics - are now taken for granted as essential tools for our public health and well-being. It's time to turn our attention to sugar."'Realistic approach' Barbara Gallani, director of food safety and science at the UK said they recognised the worldwide health burden of non-infectious diseases and agreed action was needed. "However, the causes of these diseases are multifactorial and demonising individual food components does not help consumers to build a realistic approach to their diet," she explained. "The key to good health is a balanced and varied diet, in the context of a healthy lifestyle that includes plenty of physical activity."Commenting on the Nature commentary, Dr Peter Scarborough of the British Heart Foundation Health Promotion Research Group at the University of Oxford, said taxing certain food products was something policymakers should consider.

abercrombie and fitch sale But he said taxing only one type of food could have unintended consequences, such as people cutting back on fruit and vegetables to save money for other purchases.He told the BBC: "If you only tax one aspect of food like sugar you can have unintended consequences. "If you tax fat, salt and sugar, combined with subsidies for fruit and vegetables, you'll get healthier diets." Eating like the English could save 4,000 lives a year in Scotland, Wales and Northern Ireland, a study claims.People in England eat more fruit and vegetables and less salt and fat, reducing heart disease and some cancers, say Oxford University experts.A tax on fatty and salty foods and subsidies on fruit and vegetables could help close the diet divide, they add.The British Heart Foundation says the study shows inequalities in the nations that must be addressed by authorities.Death rates for heart disease and cancer are higher in Scotland, Wales and Northern Ireland than in England, according to official figures.Diet is known to be an important factor. Last year researchers estimated that more than 30,000 lives a year would be saved if everyone in the UK followed dietary guidelines on fat, salt, fibre, and fruit and vegetables.Now, the same experts - from the Department of Public Health at the University of Oxford - have turned their attention to differences within the UK.They looked at whether deaths from heart disease, stroke and 10 cancers linked with poor diet could be prevented in Scotland, Wales and Northern Ireland, if everyone switched to the typical English diet.

abercrombie ukThey say the diet in England is far from perfect - but should be achievable in other UK countries.Over the three years studied there were nearly 22,000 excess deaths in total. Scotland had 15,719, Wales 3,723 and Northern Ireland 2,329.Hamburger tax Lead researcher Dr Peter Scarborough of the Health Promotion Research Group said: "The chief dietary factor that is driving this mortality gap is fruit and vegetables. "Consumption of fruit and vegetables in Scotland is around 12% lower than in England, and consumption in Northern Ireland is about 20% lower than in England. Consumption levels in Wales are similar. "Other important factors are salt and saturated fat consumption, which are lower in England than in Wales, Scotland or Northern Ireland."The researchers believe one way to tackle the "mortality gap" is to bring in food taxes.Denmark recently introduced a tax on foods high in saturated fat, while other countries are toying with the idea of taxing fizzy drinks or high-calorie foods.Dr Scarborough told the BBC that while the study did not consider the effectiveness of policies and interventions, the area should be investigated.He said: "Junk food taxes and subsidies of fruit and veg could be a very important tool in addressing health inequalities in the UK."The researchers say they used the English diet as their model not because it is particularly healthy, but because it is regarded as an achievable goal.Victoria Taylor, senior dietician at the British Heart Foundation, said: "This research isn't about bragging rights to the English or tit-for-tat arguments about how healthy our traditional dishes might be."This is a useful exercise in comparing influential differences in diet across the UK, namely calorie intake and fruit and veg consumption. However, saying the rest of the UK should follow England's lead to cut heart deaths isn't a foolproof solution; a quarter of English adults are obese and only 30% eat their five-a-day."The findings have thrown up some clear inequalities in the four nations and our governments must do everything they can to create environments that help people make healthy choices."