Nature Tops Nurture? Scientists Wrong Again…

They just don’t get it. Maybe they never will.

Reader Karen was outraged enough to send us a link to a news story on MSNBC that states “Nature tops nurture for heavy kids, study says. Research on twins finds that weight is 77 percent attributable to genes.” Thanks, Karen.

Read the abstract here.

Once again, the message is, “If you’re fat, it’s not your fault and there’s little you can do about it.” Bullshit. Here’s yet another theory-biased analysis that leads one to believe genes are destiny. They are not. MDA readers, please embrace this concept: You have far more control over how your genes express themselves than has ever been thought possible. Everything you eat, every move you make, every thought you think, every breath you breathe influences gene expression. Who we become is NOT immutable, NOT carved in stone, NOT a result of choosing your parents wisely. Environment and behavior are the MAJOR influences of your health, fitness, appearance and longevity. Most of you have already had a direct experience of this.

Ironically, in an editorial in the opening pages of the same journal regarding the finding, the editorial author seems to point this out:

The report by Wardle et al opens with a rather sweeping statement that the obesity epidemic is “clearly due to changes in the environment, because genes have not altered.” Evidence in the literature to the contrary suggests the possibility of changes in the genetic background of contemporary populations by factors such as assortative mating, selection (eg, increased fecundity of moderately overweight persons), demographic changes (9), and epigenetic effects (10, 11) and that these changes could be relevant in humans as well. These changes should not be dismissed out of hand.

via The American Journal of Clinical Nutrition

So I guess they get it, but they just need to prove that genes are the major drivers? Look, I won’t argue with the fact that there are some genetic predispositions to a fairly wide range of possible outcomes, but to think that obesity is unrelated to the amount of carbohydrate consumption, total caloric intake, maladaptive foods (grains, milk, trans fats), lack of exercise or even levels of stress is preposterous. You will start seeing more and more talk of the science of epigenetics – the “switches” that actually turn genes on and off – and the huge influence environment has on the epigenome (even to the extent that epigenetics can be passed on from parent to child such that what your grandmother ate can have an effect on how you develop). Yet they cling to the hope that your destiny is, well, hopeless. I leave you with the pictures of the two German identical twins Otto and Ewald who simply chose different physical behaviors and look pretty different as a result.

Just had to get this off my chest.

Photo Credit: Michael J. Rennie (PDF)

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About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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25 thoughts on “Nature Tops Nurture? Scientists Wrong Again…”

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  1. I don’t know why people love the feeling of no control and everything is to blame on someone/something else. Weird “victim” mentality people grasp onto nowadays. Those damn genes, they wronged me!

    Please….until people choose 100% control of their own health, they will never know what true health is. Too bad nothing in mainstream society provides that encouragement…including medicine.

  2. Here’s a quick recap from high school bio:

    1. Genes are little sequences of DNA.
    2. DNA codes for the production of proteins.
    3. Many of these proteins are enzymes.
    4. Enzymes are catalysts for chemical reactions.
    5. Chemical reactions are when two or more chemicals interact.
    6. The chemicals in the body come from the environment – food and drink, air, and so forth.
    7. Therefore, genes are ultimately expressed only if the environment favors them.

  3. I concur. Our understanding and misunderstanding of genes is one of the most detrimental things that has happened in the health world. While it’s done good things in terms of understanding and fighting some diseases, it’s also put people into the victim role where they go “It’s in my genes, I might as well eat these Bon-bons and drink a gallon of Coke.”

    I think a lot of these “genetic” things are really learned behaviors that come from the mother. Tying into the epigenetics thing, it’s also a sure bet that insulin resistance and overconsumption of carbs in the mother does set the child up for that. But that doesn’t make it genetic.

    Also, any chance you can go back to posting the entire article through the RSS feed rather than using the “More” link?

    Scott Kustes
    Modern Forager

    1. I know this post is old. I just have to comment. Maybe you just meant how someone was raised versus “mother”. I don’t know, but I want to scream whenever people only blame the “mother”. I have a dramatic fight with my husband daily not to eat junk in front of our 2 year old and nearly everytime he is home he takes her to mcdonalds. My friends mother tried to raise him to be thin and told him saltines were “cookies”. Granted they aren’t good for you but it was the 80’s. His grandmother undermined her and loaded him up with baked goods when she wasn’t around. So I would just like to correct the word “mother” with up bringing. Since everyone else apparently links everything bad in their life back to their mothers as well.

  4. Migraineur, great post! Exactly!

    Or as I tell my clients…your genes are like a light switch (light=good, darkness=bad)…and it’s YOU (through nutrition, exercise, environment, lifestyle, etc) who determine which ones you flip on and off. (although everyone differs in how easily they can turn the switch on/off…it’s still under their control!)

  5. What quantitative analyses and what variables does this new research address?

    There are so many factors involved, how do these quantitative analyses address the following:
    1. Prenatal nutrition – if they’re twins, then they shared the same prenatal environment, regardless of if they’re monozygotic (identical) or dizygotic (fraternal). Prenatal nutrition is obviously out of the hands of the child, but is more due to mother’s choices of food than genetics.

    2. Environment – how do the environments for these twins differ? is one twin active and the other sedentary? do their diets differ? My guess is that the environment between two twins with respect to diet/activity are fairly similar. The study would only achieve interesting results if the diet/activity of twins were widely varying, yet the twins still had similar BMI/WC (and body composition). The opening sentence of the article says “Diet and lifestyle play a far smaller role than genetic factors in determining whether a child becomes overweight” hinting that the study looked at these factors as part of their environment, but the study abstract makes no reference to these factors.

    3. What does 77% genetics vs 23% environment even mean to the average lay person? It hints that genetics matters quite a bit more than environment does. But this is quantifying something that yields little meaning to anybody, and basically reinforces what all of us already know–that both genetics and environment take part in this equation; that is, if both of your parents are hugely obese, it’s going to be harder for you to lose weight than if both of your parents are muscular/fit. Everybody knows it’s possible for both people to lose weight, and most everybody will agree that the kid with the fatter parents will have a harder time.

    This seems like a fairly worthless research study in that it doesn’t show anything we don’t already know intrinsically, and quantifying this knowledge into a meaningless number that nobody can really use to explain anything. Furthermore, it’s presented in such a way that the conclusions made are highly negative towards motivating people to change. This isn’t the sort of message people want to hear.
    But I guess one way to (incorrectly) spin the numbers is to say that if you weigh 200 pounds, then you can lose 23% (46 pounds) of that weight if you change your environment. That conclusion isn’t true, but at least it’s more motivating than saying that you’re naturally fat and there’s not much you can do about it.

  6. I shook my head when I read that misleading study yesterday. Even if one does not understand the science of gene expression, one need only look at old photos from decades past. Our genes haven’t changed much in the last century, but our diets and lifestyles sure have!

  7. one important thing that gets lost in the genes debate is the fact that genetic variability is in fact a PRODUCT of evolutionary environmental interaction. Genetic variability, not genetic defects (except in rare mutations), is how we should be conceiving it. This obsession with genetic influence on disease is a product of the current paradigm which is led by pharmaceutical companies angling for a patented “treatment”. Conceived as genetic evolutionary heritage, genes can be seen as modifying factors in pathenogenesis. In that they influence the DEGREE to which we suffer from, in this case, a bad diet.

    In fact, all the data from the turn of the century, when colonial doctors consistently reported that traditional societies were free from the “diseases of civilization” – and were consistently found to deteriorate when influenced by western foodways – showed that it is indeed nature that is the key influence.

    the reason why the establishment and researchers concentrate on drug treatment is both because that’s where the money is and because the failed low fat experiment has caused universal cynicism among nutritionists and the public. It doesn’t prompt them to question their theory’s failure, so they now seek desperately the drug route. It’s a recipe for disaster – note the recent ACCORD “study”.

    look how far we have come down the path of foolishness..

    at least there are a few good voices in this medical wilderness.

    all the best Mark (and everyone else posting)


  8. I think there is one point that probably needs to be said.

    Being obees is genetic no doubt about it.

    It loads + no exersize = get fat

    It IS in are genes its just a shame the researches (sometimes) over look this small but very impotant formula!

    Now I want geneticist to come up with a cure!

    Then I can be a couch potatoe and eat McDonalds all the time. (and toffe popcorn)

  9. Sorry I some how mispelt eat as It.

    So i mean

    Eat loads + no exersize = get fat

  10. The standard way to measure nature vs. nurture tells us how much variation in outcome comes from variation in genes vs. variation in environment.

    This means that it isn’t a fixed, objective number – it depends on how much variation in the environment there is. If everyone followed the same American diet and there was no Primal Blueprint, then heredity would be 100% – with no environmental variation, genes are all that is left. If the Primal Blueprint got really popular, so that many people had the standard American diet & exercise, but many people were Primal, that would *increase* environmental variation, and the genetic heredity number would go down!

    In other words, it isn’t an absolute number, it just reflects how much influence nature has with the current variation in nurture. It doesn’t tell you how much influence nurture can have.

  11. Ug. I have had many conversations with friends about this subject, and all I have to say is: Please acknowledge that there are some people who do have genetic factors that will cause them to be overweight. Is that true for the majority of Americans? No(We’re talking 1 in a couple thousand). However, people who have these problems and the like should not have to listen (again) to how their excess weight is their own fault. Do you blame the cancer patient for losing weight during chemo? No. Don’t blame the people with true health issues. (Ok, this is usually the point where I get asked how I can say this, so I will continue with the monologue.) Two years ago I started experiencing extreme weight gain (i.e. 20 lbs in 4 weeks). Needless to say, I freaked out. I was doing light cario, lifting weights, eating only meat and raw vegetables, keeping a food journal, and eventually tracking calories. I went into the doctor and found out (months later) that my body had stopped producing estrogen and was storing fat to compensate. All in all, I gained 55 lbs in 6 months. I am still trying to get back to my normal weight (half way there!). I will never forget the cruel comments that I received from friends and acquaintances and I make an effort to never put anyone else in that position.

    On a different note: Awesome post on women and weight lifting! As a college age female I am always suprised at how many women are proud of being weak.

    On a totally different note: Do any of the other women on the forum have problems with other women commenting on the amount of protein that they eat?

  12. A truly well constructed study would have looked at identical twins that were separated at birth. Prenatal nutrition would be the same obviously, but the environmental factors would be much more varied, and would provide for more clear data. It seems ridiculous that they came to this conclusion with a study that had twins in similar environments, this study doesn’t really seem to prove anything.

  13. Anyone looking for an excuse to stay in their sedentary lifestyle and eating the same crap will find the data to back their beliefs up and vice versa. It all comes down to what they want to believe and they will find the “study/data” to prove they are “right” and anyone in opposition is “wrong”

  14. That side by side comparison is great. Sadly, most people choose to believe what comes easier, even though it’s not the best choice.

  15. Last year i received a 3 week menu from my nephew. i scan it and printed it. i now found the 3 wk starter diet. i can only find the first page. i know thzt their were 3 pages. the one i have starts off with breakfast, nuts vegetables and fruits. i do remember something about heavy whipping cream. cannot find that sheet. any way of finding this and emailing me??????????

  16. Ewald looks like he never has a problem getting things off of his chest.

  17. “Research on twins finds that weight is 77 percent attributable to genes.. Scientists wrong again.”

    Honestly, I’m really disappointed by the starting into to your post. It seems like you’ve jumped onto the “science is wrong” track, rather than saying “science is the process of learning the truth, and we haven’t finished yet.” I find this problematic, because the goal of “learning the truth” (in a reliable and useful way) is really helpful to (me/other-health-interested-people/humans-in-general).

    Second – the exact statement here might not read the way you’ve presented it to. Say: a human will never way as much as a chipmonk or an elephant. This weight different is 100% determined by genes. It’s only within the “humanly-possible” range that nurture plays a role. Consequently, I’d rather read the statement “your lifestyle is ~30% dependent on your lifestyle, ~3% dependent on your family, and ~66% dependent on your being born human. Good luck!”

    Anyway, keep your science-related weekend link loves. 🙂 Thanks, Amy