Posted on 06/08/2007 8:07:29 PM PDT by Paradox
They are loved and endorsed by celebrities and dismissed as an unhealthy diet craze by critics. But 'low carb', high protein and high fat diets have proven their metabolic worth: scientists in the US have discovered a fat-burning role for a specific hormone stimulated by these eating regimes. The work has also raised the intriguing question of whether the Atkins diet could make you live longer.
A group of researchers led by Steven Kliewer at Southwestern University in Dallas, Texas found that a growth hormone called fibroblast growth factor 21 (FGF21) stimulates fat metabolism in the liver.
Do mice on the Atkins diet live longer?
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'It was one of those serendipitous discoveries,' Kliewer told Chemistry World. 'We were studying receptors in the liver that are activated by fatty acids, and we found that the receptors, called PPAR, regulate the hormone FGF21, so we went on to study what FGF21 does.'
Kliewer's treated mice with FGF21, either by genetic modification or direct injection, and said that it made the animals look like they were starving. 'It turned on a starvation response, even when the animals were feeding. They switched from using carbohydrates to fat stores as an energy supply,' he said.
Maratos-Flier's group fed their mice a high fat, low carbohydrate diet for 30 days and found that levels of FGF21 increased.
This biochemical deception, causing the body to burn fat even when on a high fat diet, is a weight loss method made famous by Robert Atkins, who died in 2003. Such diets are called ketogenic because, without a source of carbohydrate to produce energy, fats or lipids are metabolised, producing ketones as a replacement fuel.
Starving to stay younger
Although previous work linked FGF21 to metabolism, Kliewer's work illustrates its fat burning function for the first time. 'This is one of the most exciting things I've ever worked on,' he said. 'Starvation and restricted diet are linked to some fascinating physiology including longevity. In the long term, I would like to investigate the role of FGF21 in ageing, since caloric restriction has been linked to an extended life span in many species.'
David Moore from Baylor College of Medicine in Houston, Texas described the link between calorie restriction and longevity as a 'tantalising' research area.
'When you starve an overweight body, you see many metabolic benefits, including increased fat metabolism, some of which could be mediated by FGF21,' Moore told Chemistry World. 'There was a study described at a conference recently, where a morbidly obese child undertook a medically supervised 300 day fast. He lost half his body weight and was reported to be physically fine.'
Moore pointed out that in all species tested so far, including worms, birds, rodents and dogs, restricting calorie intake leads to a longer life span (see Chemistry World, May 2007, p24). But a long term longevity study in humans is a huge practical challenge.
Eric Ravussin from Pennington Biomedical Research Center in Louisiana has pinpointed a number of biomarkers for ageing that he says could start to answer the question of whether a ketogenic diet or FGF21 increases life span. 'This type of diet or this hormone could provide a surrogate for calorie restriction,' he suggested.
M K Badman et al, Cell Metab., 2007, DOI: 10.1016/j.cmet.2007.05
T Inagaki et al, Cell Metab., 2007, DOI: 10.1016/j.cmet.2007.05.003
Low-carbing worked for me, I lost 60 pounds in 9 months, but over the ensuing three years I put it all back on. I’m trying it again, I’m not sure how much weight I’ve lost in the past month but I’m down at least an inch on my waist.
I’ve never understood why people get so my-way-or-the-highway about diets, anyhow. There’s lots of different ways to lose weight, from just cutting portion size, to low-carb, to low-fat, to Nutrisystem-style plans that supply all the food. Find one that works FOR YOU and that you can stick with, and get some exercise. It’s easier said than done, that’s for sure!
}:-)4
I’ve followed the scientific reports on low carbing very closely and am satisfied that it’s healthy and effective if you can stick to it.
But that’s the problem- it’s harder for me to stay on a low carb diet than it is a restricted calorie diet. It doesn’t matter how healthy the diet is if you can’t stick to it.
Atkins was grossly fat, and had significant heart disease when he died.
Perhaps moderation, and moderation in moderation is the key?
Just saying....
mark
*sigh*
And the Barbra Streisand concerning Dr. Atkin’s death continues...
Do the Inuit have a long, earthly lifespan? Their traditional diet is very high in protein and fat, and low in carbohydrates. That should give some clues as to whether an Atkin’s diet could increase earthly lifespans.
So I’m wondering...you lose weight but die of heart disease from the high fat diet??
I don’t diet. I have a lifestyle eating program, in other words, this is the way i will live, not the way i lose weight.
And i’m losing, slowly.
There really isn't much debate left, as others say, its your lifestyle that you need to change. Any significant weight loss will introduce metabolism changes which will have to be dealt with for life, by, basically, eating less and doing more, forever.
'low carb', high protein and high fat diets have proven their metabolic worth: scientists in the US have discovered a fat-burning role for a specific hormone stimulated by these eating regimes. The work has also raised the intriguing question of whether the Atkins diet could make you live longer.I feel smug, having finally bought Dr Atkins' book for a buck apiece (like new, three copies, two editions) at the library.
Eliminated processed foods with high fructose corn syrup and hydrogenated oils is half the battle. The foods left over are pretty much good foods to eat on this normal-carb lifestyle. Meats, fishes, eggs, nuts, cheese, olive oil, green vegetables, yogurt, red wine...
I feel skeptical. Even if such a hormone as is in mice is found in humans, that doesn’t mean it acts the same way.
Not to say their work is of no value. It sure gives another researcher something to look at.
Intriguing question is it.
Check out the effect of ketogenic diets on epilepsy.
Most folks know the simplest ketone, acetone, the main ingredient in nail polish remover.
That group that put out the silly stats sure got a lot of milage from it. Go back and look the reality up.
Oh. Just to be a little more specific, when Atkins was admitted to the hospital, he was about 6’ tall, about 195 lbs. and in his 70s. The group that put out the description you cite was a Vegan group.
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Atkins was grossly fat, and had significant heart disease when he died. >>
Atkins was husky and not “grossly” overweight. Overweight yes, obese no. Most of his life he maintained his weight. And, btw, doctors are not immortal and do die.
And, who ever said that doctors practice what they preach. When I was a kid, my doctor had no smoking signs all over his office and when you entered his private office, what was he doing? Smoking. He told my mother, “you don’t see any No Smoking signs in here do you?”
I heard he died of a head injury nothing else was wrong with him.
Atkins was tall and broad. He wasn't "fat" let alone "grossly obese." And, he did NOT have heart disease. He WAS, however, a practicing cardiologist, who discovered that his patients got WELL on a low-carbohydrate diet.
He died of head injuries sustained when he slipped on winter ice outside his New York offce. I'm very sorry to disappoint those vegans, but they will have to come up with a different dead horse to beat.
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