Good news for couch potatoes! Even using mod cons, we burn off as many calories as our hunter-gatherer ancestors
08:59 GMT, 26 July 2012
It is news that will almost make couch potatoes jump for joy – lack of exercise is not to blame for the obesity crisis.
Research shows that, contrary to popular opinion, Westerners surrounded by mod cons don’t burn any fewer calories on a day to day basis than African tribes that spend their days hunting and foraging for food.
In other words, lack of exercise isn’t making us fat. Instead, what we eat is at the root of the growing problem.
Relax: Westerners surrounded by mod cons burn as many calories each day African tribes who hunt and forage for food, research suggests
The theory comes from American anthropologists who tracked the movements of Hadza hunter-gatherers from northern Tanzania, whose lifestyle is thought to be similar to that of our ancestors.
They also did chemical tests that provide an estimate of how many calories are used up per day.
The results showed that despite walking for miles each day in search of food and lacking modern equipment, the Hadza burnt off the same number of calories as Westerners.
Researcher Herman Pontzer, of Hunter College in New York, said this can be explained by physical activity only making up a small proportion of our energy requirements.
Staying indoors: The study found that what we eat, rather than how often we exercise, affects obesity levels
In the Hadza’s case, their daily forays for food only accounted for 10 to 15 per cent of the energy used.
The rest goes on bodily processes, from feeding the brain, to fuelling the immune system, heart and other organs.
In the West, where we generally get less exercise, our organs may burn up slightly more energy, leading to the same number of calories being used up over all.
Dr Pontzer said that ‘for the most part’ it is the amount eaten, and not lack of exercise, that is making us fat.
However, exercise is still important for general health.
The researcher, who details his findings in the journal PLoS ONE, said: ‘Exercise is important in preventing heart disease and diabetes.
'It just probably isn’t a big part of the answer for the obesity issue.’