" Obesity largely determined by genetics, says study "

[Wrangell]

Another consideration in the never ending ' nature vs. nurture ' debate when it comes to obesity.

" Genetics and heritability may account for 77 per cent of obesity, while environmental factors make up less that 25 per cent, suggests new research.

The researchers analysed the body mass index (BMI) and weight circumference (WC) in a UK sample of 5,092 twin pairs aged eight to 11 years, born between 1994 and 1996.

The results showed that the monozygotic correlations were similar in boys and girls, and greatly exceeded those of the dizygotic twins, suggesting a strong genetic influence.

Researchers concluded therefore that adiposity heritability amounts to 77 per cent for BMI and 76 per cent for WC. Shared environment effects were 10 per cent for both, and non-shared environment effects were 13 per cent and 14 per cent respectively.

The report's author wrote: "Although contemporary environments have made today's children fatter than were children 20 years ago, the primary explanation for variations within the population, then and now, is genetic difference between individual children."​

BBC NEWS | Health | Obesity 'may be largely genetic'

http://www.foodnavigator.com/news/ng.asp?n=83096-obesity-genetic-reformulation

 

[Karky]

that's an awful way of putting it.. as it makes it sound like there is nothing you can do if you have the genes to be obese.. if you're obese you might have genes to be, but I'm pretty sure that if you exercised hard and ate properly you wouldn't be.

 

[philsaigon]

It just means some people have to work harder throughout their lives not to be obese.

 

[TeenBeginner]

That is some bull. Enviromental factors play a large factor. Compare America to the many other countries, most there is a clear difference in environmental factors. Also America is the most diverse country, so if all countries had the same eating habits, logically, America would be somewhere in the avg. Also, obesity should not be weighed by BMI, but rather BF%. So they have larger BMI... ok... well that means they have more muscle to compensate for the fat. Sure genes play a large role, but I think the article is exaggerating it a bit.

 

[~LV~]

that's an awful way of putting it.. as it makes it sound like there is nothing you can do if you have the genes to be obese.. if you're obese you might have genes to be, but I'm pretty sure that if you exercised hard and ate properly you wouldn't be.

I agree.

You can be prone to it yes but I also think there are ways of preventing it through diet/training. It's sad that people are looking for every excuse in the book to justify them being overweight.

 

[Chillen]

I agree.

You can be prone to it yes but I also think there are ways of preventing it through diet/training. It's sad that people are looking for every excuse in the book to justify them being overweight.

I completely agree with you LV. I dont care what the scientific study indicates, diet and fitness with appropriate application can defy many, many biological factors. I didnt even read the article, its not worth the sweat on my brow. I have two very obese sisters, and my family has a history of being obesely over weight. I think its fairly safe to assume I have some of these genetics. I made myself the absolute exception, baby!

EDIT: Even knowing this genetic history, I also learned during my goal journey, that I have some absolutely fantastic bodily genetics that I would not have known if I had not altered my genetic disposition through diet and fitness.


Chillen

 

[Wrangell]

It just means some people have to work harder throughout their lives not to be obese.

Exactly.

I think the relevant point of the study is in trying to highlight the possible role that genetics may or may not play in someone's potential toward becoming overweight or obese.

The point being, that genetics may represent some form of ' predisposition ' - i.e Chillen's " family has a history of being obesely over weight " - rather than an ' inevitability ' - i.e " there is nothing you can do if you have the genes to be obese " - toward being overweight and or obese.

 

[theGOOCH]

Well, our genetics certainly haven't drastically changed in the last 50 years, so why has the obesity rate skyrocketed?

 

[Leigh P]

This study can not be taken seriously at all and they really wasted a golden oppurtunity but like most studies missed the boat.

The parents did all the measuring and sent the results back in and only measured height, weight, and 4 inches above the navel. Too many variables here from a high bloating diet, to off measurements or inconsistent measure times. Obesity was found through BMI measurements of just these measurements alone.

"On average, the measures taken by researchers showed children to be 1.7 cm taller and 2.6 kg heavier than the parental measurements found, "

They also only tested themselves a few times. Also..

"Children with height <1.10 m or with weight <13 kg or >84 kg were excluded. When BMI was calculated from the cleaned data, we also excluded children with a BMI < 12."

Why?

Being that the difference in WC was so small...

62.40 ± 7.08 62.15 ± 6.77 62.55 ± 7.25 62.70 ± 7.45 62.40 ± 7.03 62.28 ± 6.44 62.03 ± 7.04 62.68 ± 6.81 62.71 ± 8.03

and weight difference was so small...

33.63 ± 7.89 33.24 ± 7.49 33.85 ± 8.09 33.89 ± 8.14 33.81 ± 8.03 32.83 ± 6.96 33.60 ± 7.92 33.41 ± 7.49 34.35 ± 8.71

and the really large and really small kids were taken out of the game and those that had healthy problems I say a study that doesn't prove anything except

-Don't leave valid scientific importance to be done by mail with parents who may or may not really give a damn.

Grade of this study get an F.

 

[matt182]

Why is everyone so cynical about the study.
Stop picking strawman arguments

As the researcher said. Its not be all end all but certainly predisposes someone to becoming obese especially in such an unfavourable environment.

 

[Leigh P]

Matt there is a difference between a strawman argument and just a crap study.
You can't leave valuable data collection to thousands of different hands.

As for why it is important, the real problem of obesity is peoples lack of self awareness and accountability. The lack of understanding energy expenditure versus intake. Giving people yet another reason to blame it as to why it isn't their fault is just fueling the happy meal fire.

 

[matt182]

where did you get all those details o fthe study i didnt see any?

From what i know, the American Journal of Clinical Nutrition is pretty good.

 

[Leigh P]

Now matt how do you know it is a good journal if you don't know how to research the study it comes from eh...



Just roughing ya.

You can see that there are some other flaws in the study beyond just what I mentioned. That doesn't mean it isn't interesting, it just means that it didn't prove anything about the genetically aspects of obesity.

 

[Wrangell]

Well, our genetics certainly haven't drastically changed in the last 50 years, so why has the obesity rate skyrocketed?

Whether the obesity rate has changed or not in the past 50 years, this observation - either way - doesn't represent an adequate challenge to the validity on any contention / conclusion that obesity has a genetic component.

Obviously, the problem of obesity isn't a solitary issue of simply how one eats - but a multi faceted problem that is affected not only by one's eating habits, but by one's genetics, by a person's activity level, their lifestyle, the medications they take, their metabolism etc.

The debate is the extent to which the genetic influence on obesity is greater or lesser than the social influence on obesity - which is probably why obesity studies involving twins is somewhat intuitively intriguing.

 

[matt182]

Now matt how do you know it is a good journal if you don't know how to research the study it comes from eh...



Just roughing ya.

You can see that there are some other flaws in the study beyond just what I mentioned. That doesn't mean it isn't interesting, it just means that it didn't prove anything about the genetically aspects of obesity.

Thats a rediculous conclusion. Of course it has its limitations, it even has a whole paragraph explaining them - as most journals do. Of course it didnt prove anything but provides further evidence that genetics plays a significant part. Journals dont get published it resources like the American Journal of Clinical Nutrition if they are flawed or meaningless - as you clearly claim. Seems as though you have a polarised bias yourself for environmental influences.

 

[matt182]

The American Journal of Clinical Nutrition (AJCN) is the most highly rated peer-reviewed journal in ISI's nutrition and dietetics category and publishes the latest worldwide basic and clinical studies relevant to human nutrition in topics such as obesity, vitamins and minerals, nutrition and disease, and energy metabolism.

Can you give me one or perhaps 10 journals from AJCN that is absolutely trash and/or doesnt in at least someway contribute to the field of relevance?

 

[Leigh P]

1. There is nothing wrong with the AJCN but not everything they publish is 100%. Most studies are just jumping points to other studies and so forth. The study was crap for proving that obesity is genetically related because they allowed too many variables to fall in the hands of laymen. That doesn't mean it doesn't provide a jumping point for another study.

2. http://tinypic.com/5ppnj8

 

[matt182]

Derwyddon

Actually you begun by saying the AJCN (Or other prestiged resources) published a lot of flawless journal articles. I asked you to provide some examples which as i suspected you havnt.

In regards to your original questions directed for me that you really want me to answer.

1) Yes i do read articles
2) You would be happy to know that im actually very sceptical although not cynical. Your right, there are articles available on the web that are invalid.
3) and finally, although your last question seemed a bit dubious. No. And assuming what others may assume is not the best method for anything

Best regards,

Matt

 

[matt182]

That would be a wise move as you would be digging into a larger hole.

And just for clarity, read my statement and your response again. I mentioned specifically the AJCN and other such high class resources. Obviously you missed that important part but thats not my fault.

Anyway, back to Wrangells original discussion..

 

[tjl]

Also, obesity should not be weighed by BMI, but rather BF%. So they have larger BMI... ok... well that means they have more muscle to compensate for the fat.

BMI is easier to use for population studies because:

a. It is derived from easily, consistently, and commonly measured attributes (height and weight), unlike BF%, where measurement is more difficult, less consistent, and less common.

b. In a typical developed country population (not the people posting in fitness forums), very few people are highly muscular athletes or laborers who would have "overweight" BMIs but healthy BF%, or would be less overweight / obese than their BMIs would indicate due to some of the "excess" weight being muscle instead of fat.