T Nation

6,000 Genes Determine Bodyweight

[u]6,000 genes help determine body weight[/u]
Reporting in the online journal BMC Genetics, researchers from the Monell Center have for the first time attempted to count the number of genes that contribute to obesity and body weight.

The findings suggest that over 6,000 genes - about 25 percent of the genome - help determine an individual’s body weight.

“Reports describing the discovery of a new ‘obesity gene’ have become common in the scientific literature and also the popular press,” notes Monell behavioral geneticist Michael G. Tordoff, PhD, an author on the study.

“Our results suggest that each newly discovered gene is just one of the many thousands that influence body weight, so a quick fix to the obesity problem is unlikely.”

To obtain an estimate of how many genes contribute to body weight, the Monell researchers surveyed the Jackson Laboratory Mouse Genome Database for information on body weights of knockout mouse strains.

Knockout mice have had a specific gene inactivated, or “knocked out.” By studying how the knockout mice differ from normal mice, researchers obtain information about that gene’s function and how it might contribute to disease. Mice can provide valuable information on human disease because they share many genes with humans.

The knockout approach is so useful that the inventors of the technology were awarded the 2007 Nobel Prize in Medicine. Knockout mice are now standard tools in all mouse models of behavior and disease.

In 60% of strains, knocking out a gene produces mice that are nonviable; that is, the mouse cannot survive without the knocked out gene.

The Monell survey revealed that body weight was altered in over a third of the viable knockout stains; 31 percent weighed less than controls (indicating that the missing genes contribute to heavier body weight), while another 3 percent weighed more (contributing to lighter weight).

Extrapolating from the total number of genes in the mouse genome, this implies that over 6,000 genes could potentially contribute to the body weight of a mouse.

Tordoff comments, “It is interesting that there are 10 times more genes that increase body weight than decrease it, which might help explain why it is easier to gain weight than lose it.”

Because body weight plays a role in many diseases, including hypertension, diabetes, and heart disease, the implications of the findings extend beyond studies of obesity and body weight. Gene knockouts reported to affect these diseases and others could potentially be due to a general effect to lower body weight.

The findings also hold clinical relevance, according to lead author Danielle R. Reed, PhD, a Monell geneticist. “Clinicians and other professionals concerned with the development of personalized medicine need to expand their ideas of genetics to recognize that many genes act together to determine disease susceptibility.”

http://www.monell.org/

Very interesting article. I figured it would be something like that; quite frankly I always found the notion of one or two ‘obesity genes’ rather idiotic.

One particular part of this article really bugged me though

As Arnold has said “I can lose 40lbs quickly, easily, and painlessly by simply setting my mind to it.” It’s a fundamental flaw in the assumptions of these scientists and the population as a whole that it’s easier to gain weight than it is to lose it (for the majority of people).

You simply have to set your mind to it and FOLLOW THROUGH. It’s the psychology that gets people–they aren’t disciplined enough to deny anything that seems to be pleasurable for a greater pleasure later.

Honestly, what is this article saying that we don’t already know? 6,000 Genes help determine bodyweight? Doesn’t virtually EVERY gene “help” in determining your bodyweight by some degree? Millions of (genetically affected) processes are taking place at the cellular level of your body every second. Anyone with weight training experience should understand that just the slightest change in, say, our diet or sleep pattern, can cause drastic changes in our body weight and composition, and that the way each of us reacts to these changes is genetically different. I’m no geneticist, but I’m willing to bet that the way each of our metabolisms uniquely function is affected by more than a just a few thousand genes.

Sounds like another poorly devised excuse to stay fat.

[quote]Dirty_Bulk wrote:
Honestly, what is this article saying that we don’t already know? 6,000 Genes help determine bodyweight? Doesn’t virtually EVERY gene “help” in determining your bodyweight by some degree? Millions of (genetically affected) processes are taking place at the cellular level of your body every second. Anyone with weight training experience should understand that just the slightest change in, say, our diet or sleep pattern, can cause drastic changes in our body weight and composition, and that the way each of us reacts to these changes is genetically different. I’m no geneticist, but I’m willing to bet that the way each of our metabolisms uniquely function is affected by more than a just a few thousand genes.

Sounds like another poorly devised excuse to stay fat. [/quote]

That is the point, Bro’…YOU ALREADY KNOW…This drivel is for the Proletariat…

Yeah man, its funny (sad) to see how some people read or watch the news. Even when the news story tells an unadultered fact, people find ways to extract the very worst shred of misinformation out of it. (e.g. - Chris Benoit’s body is found with steroids in it, so that MUST be what caused his mental instability)

What bothers me about this article is where the geneticist with the PhD makes the jump to say that “it’s easier to gain weight than lose it,” and this is somehow your GENES fault.