Andrew B. Chung, MD/PhD
2012-07-26 22:33:29 UTC
http://www.bbc.co.uk/news/science-environment-18985141
By Helen Briggs BBC News
The 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 PLoS
ONE 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. They
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.
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."
Original paper at
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0040503
Abstract
Western lifestyles differ markedly from those of our hunter-gatherer
ancestors, and these differences in diet and activity level are often
implicated in the global obesity pandemic. However, few physiological
data for hunter-gatherer populations are available to test these
models of obesity. In this study, we used the doubly-labeled water
method to measure total daily energy expenditure (kCal/day) in Hadza
hunter-gatherers to test whether foragers expend more energy each day
than their Western counterparts. As expected, physical activity level,
PAL, was greater among Hadza foragers than among Westerners.
Nonetheless, average daily energy expenditure of traditional Hadza
foragers was no different than that of Westerners after controlling
for body size. The metabolic cost of walking (kcal kg-1 m-1) and
resting (kcal kg-1 s-1) were also similar among Hadza and Western
groups. The similarity in metabolic rates across a broad range of
cultures challenges current models of obesity suggesting that Western
lifestyles lead to decreased energy expenditure. We hypothesize that
human daily energy expenditure may be an evolved physiological trait
largely independent of cultural differences.
Yes, everyone needs to stop overeating.By Helen Briggs BBC News
The 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 PLoS
ONE 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. They
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.
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."
Original paper at
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0040503
Abstract
Western lifestyles differ markedly from those of our hunter-gatherer
ancestors, and these differences in diet and activity level are often
implicated in the global obesity pandemic. However, few physiological
data for hunter-gatherer populations are available to test these
models of obesity. In this study, we used the doubly-labeled water
method to measure total daily energy expenditure (kCal/day) in Hadza
hunter-gatherers to test whether foragers expend more energy each day
than their Western counterparts. As expected, physical activity level,
PAL, was greater among Hadza foragers than among Westerners.
Nonetheless, average daily energy expenditure of traditional Hadza
foragers was no different than that of Westerners after controlling
for body size. The metabolic cost of walking (kcal kg-1 m-1) and
resting (kcal kg-1 s-1) were also similar among Hadza and Western
groups. The similarity in metabolic rates across a broad range of
cultures challenges current models of obesity suggesting that Western
lifestyles lead to decreased energy expenditure. We hypothesize that
human daily energy expenditure may be an evolved physiological trait
largely independent of cultural differences.
The absolutely only **healthy** way to stop the overeating without
harmful undernourishment is to http://WDJW.net/Guard (Proverbs 4:23)
the heart (Jeremiah 17:9) by holding to the right amount, which is 32
oz of daily food.
Yes, right amount ( http://WDJW.net/2PD-OMER Approach ) control as
Chris Malcolm, MU, **and** Rod Eastman are doing is much more
sophisticated and smarter:
http://groups.google.com/group/alt.support.diet.low-carb/msg/8d2ef74488074acf?
and
http://groups.google.com/group/sci.med.cardiology/msg/522ce5c058224656?
**and**
http://groups.google.com/group/sci.med.cardiology/msg/da03131060efa3b5?
http://groups.google.com/group/sci.med.cardiology/msg/055f2e7cf3c590ee?
Don't be an Ayoob:
https://groups.google.com/group/sci.med.cardiology/msg/91c1431a6b413912?
Be hungrier, which really is wonderfully healthier especially for
diabetics and other heart disease patients:
https://groups.google.com/group/sci.med.cardiology/msg/0e719da5c2d970ca?
... because we mindfully choose to openly care with our heart,
Andrew <><
--
Andrew B. Chung, MD/PhD
EmoryIMVC.org Cardiologist
and Author of the 2PD-OMER Approach:
http://groups.google.com/group/sci.med.cardiology/msg/9ad0c19df5ffc2f7?