Does Nature Trump Nurture in Obesity?
Has Nature really beaten Nuture in the battle of the bulge, as this Times Article, Genes not poor diet blamed for most cases of childhood obesity reveals? The article makes a glossing mention of environmental factors also playing a role in obesity, but overall the article emphasizes how genes are the major constant among obese children.
Where did those genes come from? They didn’t just magically appear right before the obesity epidemic came on the scene, evolution doesn’t work that way. These genes have always been with us, which also doesn’t make sense, because obesity shortens lifespans, meaning the genes would have been selected out generations ago. The Times article knows the answer, but doesn’t give it the time it deserves so their readers can make informed personal and political choices.
Genetically, overweight people are famine survival machines. Their ancestors were better at storing energy in fat and slowing down their metabolisms than today’s skinny people. The problem for overweight people is that the environment their ancestors evolved in, where food would regularly become scarce for extended periods of time, has been replaced with our modern world of convenience, where high-energy, easily-processed foods are in abundance all around us, commonly termed the obesogenic environment. Their body’s’ fat cells–their famine-insurance–are being over-saturated. If civilization were to collapse tomorrow, and we were all reduced to foraging for roots and berries in a post-apocalyptic wasteland, today’s fat people would rule the Earth.
In fact, this sort of culturally induced diet change is nothing new. Just a few thousand years ago, humans evolved lactose tolerance in response to our change from a hunter-gatherer lifestyle to an agricultural one.
People didn’t start drinking milk to survive in ancient times any more than people today drink soda for nutrition. It takes 15-17 pounds of grain to grow one pound of meat, cattle are a luxury item, not a necessity. Milk was yummy and an agricultural abundance that allowed humans to spend mass quantities of grain on raising livestock had made it readily available. We changed our own environment, and introduced a previously foreign animal byproduct to our diet.
Lactose Tolerance was established on the many lactose intolerant souls who died and were therefore prevented from passing on their lactose intolerant genes. The lactose tolerant members of the species survived milk-drinking long enough to have children, of whom those who were the most lactose tolerant were more likely to survive to pass on better and better versions of this adaptation to drinking the product of another species mammary glands (Yuck).
Soda tastes pretty good, but shortens our lifespans. Over a few hundred or thousand years we will probably adapt to drinking so much sugar, but it will be at the expense of millions of people who will die of diabetes, heart attacks, bad knees, etc, etc. To rationalize our obesity epidemic as genetically predetermined and something we will eventually evolve out of is an unacceptable and inhuman position to take.
So environment is still the key factor in determining obesity, just not in the parental-nurturing sort of sense. Instead we have a culturally influenced environment providing sedentary lifestyle filled with unnecessarily energy-dense foods. We can blame Nature for the genes natural selection gave us thousands of years ago, but the Nurture influence of our Global Village deserves much more blame for consciously engineering a lifestyle and diet to which our genes have not adapted.
So while a cultural shift forced humans to digest milk and is forcing us to adapt to an over abundance of simple sugars, the difference between these two situations is that we have the cognitive foresight to understand the health-hazards of obesity and reason our way into fighting it. Our big brains have unintentionally created this obesogenic environment, and these same brains have the power to engineer our way out of it.
“..in a post-apocalyptic wasteland, today’s fat people would rule the Earth.”
and that is what keeps me going, biding my time…
Comment by Kav — February 8, 2008 @ 9:07 am
I have a hard time picturing Mad Max with a gut. His poor V-8 would have to be a mini-van. :(
-BMF
Comment by BMF — February 8, 2008 @ 10:09 am
I die a little on the inside every time I see the headline for stores such as the one you cite above, which appeared on the BBC website with the following gem of a headline – Obesity ‘may be largely genetic’.
Comment by YoungFrankie — February 8, 2008 @ 10:40 am
Uggg, obesity is one of those subjects that can really get me going. America is so fucking fat and many love to blame genetics. All one needs to do is look at the rest of the world. Even if you exclude third world countries, obesity is not as prevalent. Many obese people are just weak and/or lazy. Note I’m talking about really overweight people, not the “big boned” people in my comment here.
“..in a post-apocalyptic wasteland, today’s fat people would rule the Earth.”
Fuck that. Granted, they have a higher chance of surviving without food, however there are many more factors. Their body’s overall health is weak. Despite having the fat reserves, a healthy body has a better chance then an unhealthy. Obese people are generally more lazy and lack drive. I bet a non-fat person is more likely to do something to better their situation. Also, fat people lack the stamina and mobility one may need to survive in a wasteland. My whole point here is that both fat and slim people will die, and the world wouldn’t be rule by fat people alone.
As for the lactose/sugar there’s one big point you missed. Where people who didn’t evolve the lactose tolerance died in the past, they also didn’t have the medical knowledge to offset their death. I don’t see a sugar tolerance developing as strongly as the lactose. People who suffer sugar’s ill effects will not die off and as such will very easily spread their own unadaptable genes. The key (dieing off) of survival of the fittest no longer exists.
Why should our bodies evolve when we can still easily reproduce and live long lives despite the sicknesses we suffer? Hell, even if one would die they could easily donate to a sperm bank prior. We could easily get what H.G. Wells believed…a regression in human evolution.
Comment by Sour Swinger — February 8, 2008 @ 1:26 pm
I believe EVERY sentient species in the universe probably goes through a brief “awkward phase” or “evolutionary adolescence”.
It spans a period of time:
The span of time starts at the point in which modern medicine begins. Modern medicine allows those who would otherwise be culled by the natural selection process to survive and propagate when, according to Natural Selection, they should not.
The span of time ends at the point in which the species’s genome is mapped — and the ability to create custom DNA in offspring is available to the whole species.
Once the awkward evolutionary adolsence is over, genetic diseases are wiped out, genes are tweaked, and successive generations end up with better and better genes. (I imagine gene optimization and tinkering would become a growth industry for awhile.)
We’re in that phase now, but I think we’re waaay past the 50% point.
Comment by Clint — February 8, 2008 @ 2:47 pm
@Clint
Interesting idea. I just wonder if we can really master what mother nature probably does best. I’m sure genetic diseases will not be wiped out. Even if they were, something else will replace it. I truly dread the day, where every single possible sickness is cured. The very idea strikes me as Utopian.
Comment by Sour Swinger — February 8, 2008 @ 8:41 pm
You seem to use the word “Utopian” in a bad context? That confuses me.
Wiping out most genetic diseases will be quite simple. Identify, counteract, multiply. At what point will they be able to create a vaccine that actually changes your genetic structure? Or perhaps, a nanotech solution? We really can’t imagine what the future holds for us.
And while mother nature currently does it best, it also does it worst. There’s only 1 system, currently. When there are 2 systems (mother nature vs man’s control of his own nature), I have utter faith that we will do a better job than mother nature. Mother nature is random.
We just have to be careful to stay diverse.
Comment by Clint — February 9, 2008 @ 3:50 pm
@Clint
Yes, I am using it negatively. Utopia – An impractical, idealistic scheme for social and political reform. Granted it has other definitions. Ultimately, I believe a perfect society is impossible. At least in the Utopian sense. Anything that strives towards that is bad and usually means sacrificing some sort of freedom. I prefer striving to a balanced society instead.
I remember reading an article a few years ago about an experiment to change one’s genes. A couple of healthy 20 something adults volunteered. They died within the year. We still have a long way to go. Though I wouldn’t be surprised to see it in our life time. Where our parents struggled with the computer age, we may struggle with the genetic age.
I can see us easily wiping certain genes that cause certain disease, but just like with computer programming…unforeseen bugs will arise. Given a ever changing environment, new bugs/diseases can easily arise as well. Just like in computers. You could have the most perfectly stable OS, brought to a crash by some new program or hardware utilizing some new technique. So while we may wipe out one disease, another may take its place.
I like your comparison of competition. Its a good point, however sometimes random (in the long run) provides the most stable solution. BTW, I can see a lot of religious zealots being pissed off at your words. LoL.
Comment by Sour Swinger — February 9, 2008 @ 5:39 pm
Sour Swinger is right: as long as DNA replication exists, genetic diseases will exist. Even if gene therapy was advanced enough so as to cure every inborn error of metabolism known to man, new ones would still pop up in every single generation of people born.
And also, while mother nature may be random. On average she does a way better job than we could ever dream of doing. At least for the foreseeable future anyway. As long as our environment is changing (and by environment I mean everything that isn’t our genes) evolution will allow adaptation in a more efficient way than we could design ourselves.
Comment by YoungFrankie — February 10, 2008 @ 9:30 am
I don’t think you can so easily dismiss the possibility of construct DNA that contains some form of parity information, automatically erasing certain harmful variants (but permitting others, for diversity’s sake). Once we understand what we are working with, some error-correcting protocols can probably be established to stop certain bad random mutations.
Quite simply, adjusting a line of genetic code via computer program is going to be faster than evolution, which is a very very slow process. We have time on our side. We don’t have to be more efficient, just more persistent. Natural evolution is S-L-O-W.
Comment by Clint — February 10, 2008 @ 2:16 pm
Clint – What’s the rush?
-BMF
Comment by BMF — February 10, 2008 @ 4:44 pm
What’s the rush to start using tools? What’s the rush to map the human genome? What’s the rush to explore space?
Comment by Clint — February 10, 2008 @ 7:31 pm
@Clint
Perhaps nature takes its time so it can properly test the changes. Those changes that work well, get passed on. Hence, survival of the fittest. Which brings a sense of irony when we have our own genetic tinkering in a world where survival of the fittest no longer applies.
I think the tortoise and the hare metaphor applies well here. Slow and steady wins the race. Mother nature may move slowly, but its very stable. It has allowed a delicate balance of life to remain intact.
I was just reading a few days ago, about a species of moth that evolved an immunity to pt Corn. (Genetically Modified corn that “natural” produces its own pesticide). Only took the moth 10 years. My point is that we could remove a gene for a disease and find 10 years later it doesn’t work as intended. By then, we’d potentially have thousands if not millions of people with bad genetic codes.
Comment by Sour Swinger — February 10, 2008 @ 8:59 pm
Nature doesn’t purposely take it’s time to test changes — That’s a side-effect of a slow, dogmatic, inefficient system.
It takes awhile for all the less evolved to die out. Why wait?
If we can develop a new artificial gene that, say, gives people 20/1 vision instead of 20/20 vision — give it to everybody.
If you find out 500 yrs later that it comes at a great cost, revert it. We wil have that power.
Why should billions of people live their lives with 20/20 (or worse) vision, in the name of some great natural “test”? Putting all your faith into the process of evolution is about as silly to me as putting all your faith into creationism.
We don’t need to wait thousands or millons of years to test. And anyway — Test what? Does nature have a test plan? Nope. It’s test plan is “spring them all on the world and see who lives”. It certainly works, but it seems to me to be the slowest possible way to arrive at a conclusion.
And natural selection with human beings stopped awhile ago. Those of us with 20/80 vision are NOT dying out to make room for those of us with 20/20 vision. It just isn’t happening. Evolution is too slow to keep up with our human decisions.
Personally, I absolutely do not think the tortoise and hare metaphor applies at all.
If the tortoise is so superior to the hare, we do we even have polio vaccinations? Why have any vaccinations at all? It’s just an arms race. We should just patient wait, and in a few million years (maybe a few decades, if we have a moth’s luck), all our problems will naturally fix themselves, right?
Aids will go away. Tubuerculosis will go away. We shall put our faith in mother nature to take care of all of our problems. There is no need for science to interfere in these holy and revered natural processes!
As for your 10 year argument — I am operating under the assumption that our code can be tweaked mid-life. So if you find out your tweak has a recall, you go down and get that gene reverted. Quite simple.
And if you want to operate on the assumption that genes CAN’T be tweaked in mid-life (which I think is a bad assumption, eventually we’ll be able to do almost anything), then there will simply be more government oversight.
You know — What if a prescription drug is released, and 10 yrs later it doesn’t work as intended?
Oh wait. That’s happened. Vioxx, and others. We already have a process in place for dealing with your “what if” scenario.
I am just not understanding your skepticism. It seems almost luddite to me.
Comment by Clint — February 11, 2008 @ 8:37 pm
@SourSwinger:
“You could have the most perfectly stable OS, brought to a crash by some new program or hardware utilizing some new technique. So while we may wipe out one disease, another may take its place.”
Yes. And with a computer, we adjust the code, and a new release is put out. Often within HOURS of an announced vulnerability.
Point being: Our own ability to maintain and manipulate a codebase is waayyyyyyyyyyyy faster than evolution. Hell, just about any man-made process PERIOD is faster than your typical evolution.
Once we understand our own codebase, we can fix our bugs quickly and easily.
It would also be logistically impossible to tweak 100% of the population at once, so it’s not like every human being on the planet will get the spontaneous combution gene and go up in flames simultaneously. There will still be diversity (or we’d all be identical clones…)
I just don’t see the sky falling with this one. I think it’s inevitable. And we’re certainly not going to be able to explore the cosmos with the genes we have. For starters, we could use bodies that can withstand more radiation, more g-forces, and more extreme temperature ranges.
Why terraform a planet when we can probably adapt ourselves to the planet with greater ease?
Comment by Clint — February 11, 2008 @ 8:50 pm
@Clint
My skepticism comes from my already strong belief in survival of the fittest. I am against taking medicine until I absolutely must. I hate that my eyes are not naturally 20/20. I hate getting sick. I hate letting sickness bring me down. Basically I hate being weak. I fear gene manipulation among humans will be a bad thing.
I know we won’t be able to stop the ability to change genes. I’m sure the generation that grows up with it, will be a hell of a lot more open to it then the one it was introduced into. Guess similar situation to when computers were introduced. I try to stay open to it, however I know it’s definitely not for me.
Comment by Sour Swinger — February 11, 2008 @ 10:12 pm
It sounds like you are transferring (i.e. psychological “transference”) your own disdain of your own imperfection (which we all have) onto a concept that has nothing to do with the present.
If you truly believe in survival of the fittest, if you truly believe 20/20 vision is a good thing — I think you have to accept that we’re not ever going to evolve it. To become “the fittest”, we have to take control of our own destiny.
Think about how when we invented fire, and when we invented the wheel. Both of those inventions helped us depart from being governed by mother nature as much.
For example, Fire let us be warm where mother nature would have us freeze to death. Maybe this is why we don’t have fur? Or maybe our lack of fur inspired us to create the fire in the first place? Or maybe both happened at once. Point is, if another ice age came along, we would not survive it without fire. We left mother nature in the dust a long time ago in terms of shelter. And I believe not only us humans, but every sentient species in the universe, will ultimately leave mother nature behind in terms of evolution as well.
I should name my theorem. It seemed to work well for Ryan’s theorem :)
Comment by Clint — February 11, 2008 @ 10:59 pm
LoL. Perhaps we have no fur because god create us as such…….j/k. :D It is odd, that we are the only animal on the planet that controls fire. We don’t necessarily run from it.
Yeah I see your point. Survival of the fittest may still play a role though, just not in the context we normally associate it to be. No longer physical/health aspects but socially and economically. More of how we relate to the rest of humanity. No matter how far advanced we go, mother nature shall always deal a good hand with/against us.
Disdain is such a harsh word. how about disappointment in my own imperfections. I’ve already accepted that we won’t evolve pass some of our imperfections, such as vision. However one could say we are evolving to by pass those obstacles through our science. I.E. laser eye surgery. Which takes us back to fire. Perhaps mother nature intended us to evolve in such a manor to win via reason not pure physical toughness.
This can lead right back to gene tinkering. Perhaps mother nature intended us to evolve our genetic code on our own volition. She provided us the evolutionary path to gain enough intelligence to do so. Perhaps like a human mother, she intends for us to leave house and start a place of our own. A place far out of her reach. As such, we’ll need to continue to grow on our own.
Comment by Sour Swinger — February 12, 2008 @ 2:01 am
Wow, that’s pretty poetic, SourSw. Considering you were arguing on the opposite side, I applaud your open-mindedness.
Comment by Clint — February 13, 2008 @ 12:59 pm
LoL. Not sure how that’s poetic, but I’ll take the compliment. I was kinda arguing the other side since you took the one. We got into a discussion I haven’t really put genuine thought into. These posts are like an evolution (pun intended) of my own random thoughts forming into a solid opinion.
Being open-minded is definitely hard. I just know I don’t wanna be like my parents who couldn’t understand the ideals of the younger generation. I’d rather grow with each successive generation. Granted I’m still struggling to accept Rap. Hip-Hop i’m fine with…but Rap. Uhg.
Comment by Sour Swinger — February 13, 2008 @ 8:36 pm
lots of americans and europeans are getting obese these days because of over-eating. people should be controlling what they eat or they should workout their body to burn fat.
Comment by bodydetoxdiet — August 3, 2009 @ 11:03 pm