'Fat muscles' may explain obesity

[Lez]

'Fat muscles' may explain obesity

Exercise encourages the body to burn rather than store fat
People who are overweight may be able to partly blame their muscles for storing too much fat, a study suggests.
The muscle of severely obese people appears to be programmed to amass more fat compared to that of lean people, US researchers at Duke University found.

This programming, which is down to a gene, might also explain why some obese people find it hard to keep weight down despite cutting calories, they said.

Targeting the gene with drugs may help, they told Cell Metabolism journal.

Until then, plenty of exercise seems to be the most expedient way to weight loss among individuals with the gene, although a healthy diet is also important, they say.

Dr Deborah Muoio and colleagues studied the muscle cells of severely obese and lean humans in the lab.

Fatty muscle

They found that the fat-building enzyme stearoyl-CoA desaturase-1 (SCD-1) was three times more abundant in the muscle from the obese people.

SCD-1 slows down fat burning and promotes storage of fat droplets in the muscles.

When the researchers used genetic techniques to alter the cells of the lean individuals so they also had higher levels of the enzyme the cells began to store more fat.

The study authors believe people either inherit the SCD-1 genetic predisposition to obesity or develop it at some point in their life, possibly triggered by a poor diet.

Dr Muoio said exercise would probably help fight this type of obesity because regular physical activity encourages changes in the body to burn rather than lay down fat.

This work contributes to the reasons why people might be at risk of gaining weight but it is by no means the one and only answer

Dr Toni Steer, a nutritionist with the Medical Research Council

She added: "Obesity is a very complex disease and this metabolic pathway does not fully explain obesity but it is a likely contributor.

"The cells of obese people remember their metabolic programme, which could help explain, in part, why losing weight and maintaining weight loss is so difficult. The good news is it's possible to change your energy balance through exercise."

Dr Toni Steer, a nutritionist with the Medical Research Council, said: "We know that genes only explain about 30% of obesity. The other 70% is down to environment and other lifestyle factors.

"This work contributes to the reasons why people might be at risk of gaining weight but it is by no means the one and only answer.

"Also, a number of genes may be involved.

"The best way to lose weight is to eat healthily and to exercise. Even if there was a drug available, adopting healthy eating habits and being more physically active would still be important."

http://news.bbc.co.uk/1/hi/health/4329854.stm

[kebaldwin]

That is an interesting view -- normally this problem is viewed from the insulin / carbohydrate perspective.

I learned somewhere that a simple way to think about it is -

carbohydrate lessens muscle and builds fat

protein lessens fat and builds muscle

this is obvious in people with type 2 diabetes but not in the people that do not have type 2 diabetes tendancies

[Samuel]

Exercise encourages the body to burn rather than store fat
The muscle of severely obese people appears to be programmed to amass more fat compared to that of lean people, US researchers at Duke University found.
Dr Toni Steer, a nutritionist with the Medical Research Council, said: "We know that genes only explain about 30% of obesity. The other 70% is down to environment and other lifestyle factors.

Although blaming it on muscles is alittle unusual, what they say is very close to what I believe in. At least they are not saying "there is nothing wrong with obese people. All they need to do is to eat less".

Here is the theory which convinces me:

I think that our self weight control is made of 2 components:

(1) A set weight.
(2) A mechanism which guarantees keeping us all the time at that set weight.

The set weight is not the same for all. At the time of our ancestors, there has been a different set weight for every person depending on the environment he lives in. This is because the amount of body fat required for a vegetarian who has an inconsistant food supply for example, must be higher than the amount necessary for a person whose diet is mainly meat.

We inherit the set weight from our parents and normally keep it unchanged for life. However, some factors can change the set weight amount. Yoyo dieting for example, can make it go up each time we go through "lose weight-gain it back" cycle.

Whenever the weight stabilization mechanim breaks, we become unable to stay at our set weights, so our weights balloon.

People of the sixties and earlier have had different weights, mainly because each one has his own unique set weight. People of today have an additional reason for gaining weight which is that their weight stabilization mechanisms are defective.


When they say that genes explain 30% of obesity and other lifestyle factors explain the other 70%, I see that they mean 30% of the people are obese by their set weight and the rest are obese because their weight stabilization mecanisms have been damaged.

Also exercise may affect set weight just like yoyo dieting. Yoyo dieting is interpreted by the body as living in an environment with interrupted food supply which requires more body fat. Also exercise, especially running could mean to our bodies that we could be in danger and the need to be light surpasses the need for high energy reserve.

[kebaldwin]

IMHO

I think that setpoints are not points that your body want to maintain weight but points where your body makes major changes.

For example, people with type 2 diabetes (i.e. us) don't gain weight to a setpoint and then stop gaining. We gain to the setpoint, pause (change muscle to fat or add more fat), and then resume gaining weight.

I think that people that are overweight are the people that would have been the healthiest 10,000 years ago because they could easily store fat and then live off of it for days untill the next big kill / hunt / feast.

But today with a constant, never ending, food supply the healthiest people turned into the unhealthiest.

[Stephbme]

Could this exsplain why I gain weight when I exercise? I will be loseing very well and then start working out and I stop losing and start gaining! It drives me nutts but I love working out. Should I lose the weight first then workout?

[kebaldwin]

I am not sure what kind of exercise you are doing, what your goals are, etc

But you could very well be losing fat and adding lean (muscles, organs, bone, etc) and therefore your weight not change or gain.

Do you still lose an inch over about 3 or 4 months even though your weight does not change?

[southbel]

I think this is a very interesting article. When I was young, I exercised a lot. My parents had their heart set on an Olympic athlete. This continued until after I got out of the Marine Corps with a blown knee. Since I have not been able to exercise at that level, I gained weight rapidly. I have seen this trend in my family, especially those with similar physical characteristics, such as eye and hair color (when the dominant gene is present for these characteristics). Even as an extremely fit athlete, I always battled the bulge.

I honestly believe that a propensity towards obesity exists and for those people, a dramatic dietary change (not just less calories) is necessary, much in the way diabetics change their diets. For me, the ONLY thing that works is less carbs and more protein. What would be a very interesting study is a low-calorie diet vs a LC diet in people with this gene. I rarely get interested in studies done on obesity since most tend to use bad science, but this one definitely got my interest!

[ItsTheWooo]

Pardon me if I am totally wrong, but I thought that muscle cells becoming marbled with fat is one of the hallmark effects of a high carbohydrate diet?
Cows fed grain have the delicious marbled meat that we all love... cows fed grass do not.

This is yet another example of researchers seeing the symptom but missing the big picture. SCD-1 is very likely released in response to aggrivated/high insulin levels. It's another part of the "fat making machine" that your body becomes when carb sensitivity is out of control. This is why obese people have three times as much as lean people.

The study authors believe people either inherit the SCD-1 genetic predisposition to obesity or develop it at some point in their life, possibly triggered by a poor diet.
I'll wager it onsets/triggered from hyperinsulinemia & insulin resistance.

That's why exercise was observed as helpful for controlling the expression of this gene. Exercise helps reduce insulin levels, and increase insulin antagonist hormones. It has a beneficial effect on the IR. Seeing as this gene is just a tiny part of the complex enzymatic & hormonal changes that occur in IR, it stands to reason that exercise would help it.

[Trinsdad]

What's this "Excercise" stuff?