Topic 5 - Genetics And Weight
I must start off with my favorite quote in the entire book:
It’s common knowledge that obesity runs in families. But there’s debate over the reasons why – is it nature or nurture? Biology or environment? Or a combination of the two?
Rethinking Thin comes down firmly on the side of weight being determined by genetics:
It takes the position that we’re all born with genetically determined weight ranges of perhaps 20 – 30 pounds and within that range, it’s not difficult to manipulate weight up and down. But, the theory is that it’s extremely difficult to take the body outside of it’s comfort zone, whether above it or below it. The body will fight hard to return to its set point or comfort zone.
To me, the science linking weight to genetics is compelling. But what the book glosses over is that we’re talking about genetic tendencies here. And a genetic tendency has to be nurtured in the right environment in order to be expressed.
When my son was diagnosed with diabetes at age 17, we were shocked because we were told that diabetes is a genetic disease -- but there was no diabetes on either side of the family. Ah, the doctors said, there has to be an environmental trigger in order for the diabetes gene to be expressed. It’s a genetic tendency with an environmental trigger. So the gene may have been there for generations but never triggered.
I kept thinking about that as I read about weight and genetics. Weight being determined by pure genetics can't be the end of the story, can it?
Take height, for instance. The average American today is three inches taller than during the Civil War (from the book). Genetics haven’t changed in that time; the environment changed with better nutrition and less disease. In today's environment, that same height gene is fully capable of being expressed.
Likewise, even if weight is as tightly controlled by genetics as the book argues, it still needs the appropriate environment in order to be expressed. A gene for obesity is going to find a pretty hostile environment in rural Africa, but in the United States today, conditions are such that it can flourish and be fully expressed.
In light of the book's agenda, it's not surprising that it doesn’t deal with the question of why – if weight is indeed genetically controlled – have the levels of obesity risen so dramatically in the past three decades? Certainly we haven’t had enough time for our genes to have mutated, so what did change? Could it be -- the environment?
What do you think about the studies cited in the book? What are your thoughts on weight and genetics? Are we absolving ourselves of responsibility if we believe that our weight is genetically determined? Or can the awareness that we may have the genetic cards stacked against us make us more careful and vigilant about our environment?
Is the book conveniently overlooking the role that environment plays in the expression of genes? If environment is the trigger for obesity genes, what are the implications for the world we’re raising our children in today?
How about your family? Is it an obese or overweight one? What about the environment you were raised in? What do your personal experiences tell you about genetics and weight?
Please share your thoughts and reactions. :)
I came across a comment somewhere recently, maybe even here, where it was said that even with a genetic predisposition to obesity, if you are born in a third world country in a life where poverty & food scarcity are your reality, then you obviously will never be able to become obese.
I completely believe in the fact that a predisposition to obesity is genetic, but I also buy the concept that it needs an environmental trigger. Assuming this is what is happening, it explains a lot about our obesity epidemic that has arisen over the past 50 years. The change in food supply and availability over the past 50 years is incredible. I can see how it could awaken a dormant predisposition to obesity in the population.
Meg wrote, "What do you think about the studies cited in the book? What are your thoughts on weight and genetics? Are we absolving ourselves of responsibility if we believe that our weight is genetically determined? Or can the awareness that we may have the genetic cards stacked against us make us more careful and vigilant about our environment? Is the book conveniently overlooking the role that environment plays in the expression of genes?
Let me respond to each -
What do you think about the studies cited in the book? - I had heard about some of the studies cited before I read the book. For me, reading the book confirmed some of what I had previously learned. And then, my experience with myself and others I know is consistent with the book's premises.
What are your thoughts on weight and genetics? Are we absolving ourselves of responsibility if we believe that our weight is genetically determined? Or can the awareness that we may have the genetic cards stacked against us make us more careful and vigilant about our environment? I believe that other things being equal (e.g., no lack of food available, no illnesses), genetics influences weight. If we are looking for something to "blame," we most certainly can blame our parents/grandparents for yet one more problem they bestowed on us. If, on the other hand, we are looking for a way to get rid of the weight for good, this information can aid us in developing and implementing a plan to lose weight and keep it off. The plan I have developed - slightly modified since reading the book - is to lose an initial 15% of my weight around 30 lbs - and then, to maintain that for at least one year before working on the next 15%. I am hoping to "re-set" my "comfort zone."
The last question - Is the book conveniently overlooking the role that environment plays in the expression of genes?
I don't think the book overlooked the role of environment. It dealt with the influence of the diet industry and with marketing, media, and models/actors/actresses. It also dealt with the increasing amounts of food put on our plates at restaurants.
I think the author covered her bases here. Remember, 99% of the books out there focus on the environmental issues with little or no mention of the genetic issues. Not a bad thing to have one book view the problem from a different point of view.
To me, it's a matter of both genetics and environment. Some of us are programmed to store fat more quickly and more efficiently than others, but we weren't engineered either to be morbidly obese--that is a result of environmental factors. I fail to see how a really high level of stored fat, save in rare cases such as the one of the leptin girl, could have been conceived as a natural mechanism, because it completely defies to point and tendency of evolution. If the mechanism has gone haywire, I'd bet it's because it wasn't given a limit simply because there wasn't any need for a limit (the way Earth used to be, we weren't meant to live in a surabondance of food)... and we've been pushing those limits more and more with inappropriate quantities and uality of food. Cf. some countries in which food circumstances aren't favorable, and people have a hard, hard time even trying to put on a just a few more pounds. If we all had to live in the savannah, hunt our own food, pick our own fruits and keep on the move constantly for more food sources, we probably would have a hard time gaining on weight quickly.
To put it in terms that my colleagues at work would like, "if it's not broken, don't fix it". We've tried to fix something that wasn't broken, and now we've indeed broken it. Great. Back to the drawing board?
Okay. So there is a genetic predisposition, and I think the author put it into light well enough, but I'm really not convinced that this should ever be used as a convenient excuse. We were made to adapt, now it's time to adapt to that as well, hard as it may be. The role of environment IMHO is just as much, if not MORE important that that of biology. And I'm still sticking to my guns: the process of storing fat more easily isn't a curse per se, it has just become a curse because our world has made it so. :)
(There are other things I want to add, regarding the studies on twins, but I don't have the book with me now, so I'll post again after having double-checked the info.)
I'm going to pop in for a sec without the book. I wonder when the library is open and if I can get it back.
The gentics thing hit home for me. I 'thought' I was a sturdy Flemish woooman. However, when I stopped to think about my parents and grand parents ... hmmm .... one was obese and died that way. A couple were heavy and a couple were rail thin. That was an eye opener for me.
Nurture? While food was important at home. Snacks were not. We had meat, potatoes and home grown vegetables. One serving of each. There were six of us and not much money. A chocolate bar was a treat that Mom brought home with the groceries. One for each. I don't think I had pizza or McDonalds until I was a teenager.
All that means nothing very clearly to me ;)
I found the twin studies very compelling but not insurmountable.
I have no answers to most of these questions. I can share my personal family experience though to add one more data point if it would help.
My father and his sister are both obese, and my sister is borderline between overweight and obese (about where I was before I started losing). My mom had been overweight but recently lost it -- she was never overweight until after having kids, and never as severly as my dad or me & my sister. My mom's family varies from normal range to very slightly overweight. My dad's mom was overweight when she was younger and became thin as she got very old. Of my two cousins on my dad's side, one has always been normal weight, one was obese and then lost the weight after her divorce. Her two kids have varied from normal to slightly overweight, never more than that. So there is the nature part.
As for nurture, food has always been HUGE in our home, especially among my dad's family, who I grew up with. Every family event involved a big dinner, the more special the occasion, the bigger the dinner. Every good thing was celebrated with food and every bad thing comforted with food. If I see my parents after a long absence, I don't hear "I love you," I hear "Where do you want to go for dinner?" They mean the same thing in my family. This is why I have such a hard time believing that environment could possibly play such a small role.
Aside from the issues about emotions and food, we also went out to eat multiple nights a week (especially after my mom started working full-time when I was in high school), always had dessert on hand (the only rule about dessert being that we had to eat a piece of fruit before we were allowed to eat dessert, but that rule magically vanished once we were old enough to get food for ourselves), and ate lots of high-fat meals. Once, after I had lost some weight, I went home to visit and offered to cook dinner. I cooked a chicken stir-fry and served it with rice, and my dad's comment was "It's not fried!" I think he was joking, but seriously any stir-fries he ever cooked had the chicken fried first (they were delicious, btw). Our eating habits were terrible. Fast food multiple times a week, dinner out multiple times a week, lots and lots of prepared foods. "Exercise" was always a dirty word. Breakfast on the weekends was IHOP or Jack in the Box. Yes, we did eat better when I was a little kid. But really, I have very few memories of that, and a whole lot of memories of eating junk when I was in high school.
After learning those eating habits as "normal," I feel like it's no surprise that I ate way too much junk in college. As part of my weight loss journey I have had to learn what "healthy eating" means. No, I was never taught it in school. I had seen the food pyramid but that's about it. It never occurred to me that eating out all the time was unhealthy, or that I ought to be exercising, or that dessert every night could be what made me fat. I told myself "I just come from bad genetics" and used it as an excuse for being fat. When I nearly failed gym class I said "Oh, I just have bad genes, that's why I can't run an eighth of a mile without getting out of breath."
Maybe if I had been eating and exercising like I do now my whole life, I would have been fat anyway. I don't know. But I find it really hard to believe that the environment I grew up in didn't play a huge role in my obesity.
I haven't read the book but I plan to but I definitely have an opinion about this.
I think genetics have determined my fate somewhat. My belief has always been that my genetics have determined me to be overweight but my actions have determined how overweight I got. It has been something I've wrangled with because I don't remember an abnormal child hood of eating anything out of the ordinary but I was 300 lbs when I was 14. I do remember eating an excess of "normal" things though.
Ever since I was 4, I was "chubby" but beyond being chubby, I also developed an eating disorder which propelled my weight into the obese category before I hit my teens. As a result, I believe I developed PCOS which in conjunction with my excess eating gave my weight an extra push before I entered high school.
Anyway, looking back on my weight gain in my early years, I believe it is a bunch of genetic tendencies which I didn't fight nor did I probably know how to fight that pushed me to 300 lbs.
Of course 300 lbs wasn't my highest weight. I gained 30 lbs in 5 years of college, mostly a result of the lifestyle being distracted by college, not paying attention to my weight and continued excess eating. I ended up gaining 30 lbs after college within a year due to getting a car, lack of natural exercise and continued eating issues. It also took me 5 years before I would successfully start to lose weight even though I tried throughout those 5 years.
Personally, I don't like the "genetics make me fat" argument. I think it holds people back from losing weight. Why try if my own genetics are fighting against me? Genetics may make it tougher to lose weight, genetics may make gaining weight easier, but I think genetics don't make you fat all on their own.
My Mom has always been around the size I am now. My DH is fond of saying, "Science has no answer for how much ice cream your Mom can eat [and not gain weight]" She can easily eat a gallon of ice cream laiden with chocolate sauce over the course of a weekend. It's the luck of genetics that lets her do so.
When I was dating, I often surprised my boyfriends by the amount I could eat when they took me out to dinner. I always finished my plate and ate all my dessert. I was asked, "Do you have a hollow leg?" I thought they meant that other girlfriends didn't finish their dinners in order to appear sheik or something. Or that they didn't think a small person could eat as much as I did and not gain weight.
Then, I went on the medicine that put my hunger into overdrive and my eating vastly increased. For the first time, the more I ate, the more I weighed.
I agree with the conculsions of the studies on twins raised apart that our weight is tied to genetics. That you're either thin or not thin, i.e. have the tendency to be heavy. I don't know if thin people process the food they eat differently than not thin people. I don't know if the quantities they eat are different based on different levels of hunger. I didn't see any study datum in the book that discussed these theories.
However, I believe that the environment of fast foods, convience foods, and high fructose corn syrup in just about all packaged goods pushes people from being slightly overweight to being obese and beyond.
And that emotional eating increases the quantity of food consumed which leads to obesity.
Right, here it is. I checked back to the chapter with the studies conducted on identical twins, and the conclusion that "almost all of the differences in weight in a population are due to genetics". That's what I had in mind earlier on today, the key word being "a population". As in, the research mentions twins being reared apart, but is there some place to check what this "apart" was? I.e. if both were, said, in families of the same country and approximatively same social level, what does it say the most: that genetics are really so much more important, or that the difference wasn't so blatant because the environments themselves weren't that different?
For instance, if in a pair of identical twins, one was raised in a standard American family and the other in a traditional Japanese family (with traditional food, that is, not western food), would the second twin still be as overweight as the first one? I'm not sure the studies took that into account, but I didn't find many details either, so...
(I'm using the Japanese/Asian example, because it's not rare to see a person of Asian origin remain thin if on their traditional diet, but grow overweight if eating the western way. Cf. the author of the "Japanese women don't get fat" book, who did get fat when she switched to pizzas etc. during her studies. I guess she would be a person with a tendency to gain weight--genetics--but her normal environment wouldn't let this appear, sort of.)
I need to fully read that chapter again, anyway.
Well, I think that it is too fatalistic to say that it is all genetics and there will be barely anything we can do about it if our 20-30 weight range puts us in the 300lbs range.
We do have some control. It isn't all nature and it isn't all nurture.
I actually found the book very disheartening because the main thesis was that weight is largely determined by genetics and even if you weigh 272lbs it will be nearly impossible to lose more than a couple lbs and keep it off. Oh, and if you do want to keep it off you will have to put your body in starvation mode--- permanently. Great. So, there's hope for us all then *she says sarcasticly*. So what the **** are we all doing here then? What is the point of our efforts and 3fc?
I feel that the author's answer would be a soft shrug of the shoulders and a knowing nod of the head and a comment that "Well, a immense minority can succeed, but many of you are just going to fall of the wagon time and again and will never win this battle."
Seriously, that is the vibe I got from this book.
But I choose to believe in hope. I think that there is a point to our community and our individual efforts. I think that it is entirely possible for even most of us to lose weight and keep it off. Maybe not 100's of lbs, but something.
I found the book very interesting but was very disappointed in that it seemed to validate what all of the pro-fat campaigners preach and almost dismissed the fact that any valiant efforts that people make to lose and keep weight off is next to impossible and very likely to fail.
I felt like a curious oddity reading the book because, here I am, sitting down with my glass of water and carefully thinking about all the points the author makes, and she indicates that I am a rare, rare individual (because I have lost, by sensible diet and exercise, over the course of three years, 140lbs). And, maybe I am in the minority with this, but I saw it as offering nothing but bleak dispair to all those who are currently trying to lose massive amounts of weight.
Oh, yeah, this was about genetics, right. So, getting to that point, I would have to say that one of my parents is obese, and only one of my grandparents was slightly obese and to my knowledge, none of my great grandparents were obese (maybe one or two of the eight were slightly overweight). And my only sibling was thin, thin, thin as a child and now in his twenties is muscular, muscular, muscular (but, now he realizes that he has to work a bit harder to keep that beer belly at bay)!
So, genetically speaking, there is possibly hope for me yet. And that, my friends, was the one piece of positive news I gleaned from that book. :)
I agree with ya Charlotte. I ended this book saying, well ****, it's genetics and a very big, money laundering industry, this WL business. I was ready to cancel all my magazine subscriptions, stay out of the stores that tempt me with current issues to the ones I don't subscribe to, and refuse to raise the circulation counts in the library for any more diet books. I was just going to eat right, do cardio 3/wk and lift once a week and just see what happens. Let nature take its course, so to speak. Where's the race? I'm not sure how I feel now - not quite so over the edge, but not necessarily motivated to run a marathon either.
Wasn't there a study published recently that stated genetics affected your weight by 5% and the other 95% could only be attributed to behavior?
I believe genetics or nature make the largest contribution to obesity, but that nurture, or environment play a role, in the way that the rest of you suggested.
I agree with shrinkingchica that the conclusions are disheartening. But when you think about it, aren't the folks on here who have lost large amounts of weight and kept it off, in the minority? Kolata is not saying that no one is sucessful, she is saying that very few are sucessful. Do we hear an irresistable challenge here?
I think that the people who participate on this site over the period of a large weight loss and subsequent maintainence are very special folks. To me, they are similar to people who go to AA for alcoholism. Very few people who go to AA are permanently successful (as in dying sober). Some are, however, and they are the winners, as the loosers (no pun etc.) are the winners here. Now don't anyone get upset about my alcohol analogy. I happen to believe that alcoholism has a large genetic component and that alcoholism is not a sign of moral decrepitude! An alcoholic must be forever vigilant. So must a former "Fat Chick". Ultimately, some few of us can live with the vigilance in exchange for quality of life.
I think that Kolata believes that because obesity is genetic, that there will eventually be a medical cure. It will be like taking insulin for diabetes. And probably diet and exercise will be suggested as a way to avoid being dependent on anti-fat shots. So, there we are, right back where we started.
I also agree with hrbabe,
do I believe genetics plays a role....absolutely
do I believe that there is a 30 lb range? maybe. I know a lot of women my height who weigh down in the teens, I just dont see that as possible for me.
do I believe that I have lived the majority of my life in that range? Absolutely not. I think my "genetic weight range" if there is one is probably 120-140 ish. Maybe a bit higher or lower.
I also know that I systematically was taught to overeat as a kid
I know that I was rewarded for eating well and punished for not eating
I know that I use food for emotional and spiritual reasons and not just fuel.
If I conquer all the last 3 and still cant lose weight, then and only then do I think I can blame it on genetics.
There are some things that might be true.
I do think that I am not capable of eating only 1200 calories a day. I think attempts to do so in the past have led to some of the failure cycles the author talks about.
But for me to sit there at 184 lbs sedentary and eating enormous quantities of food and blame it on either genetics OR upbringing is denying my own responsibility. Yes, my parents didnt teach me how to eat well, but guess what..I am 37...its time for ME to teach me how to eat well.
After thinking about it, I don't think it absolves us of responsibility, but it may make it more difficult than is worth my while to lose a lot more weight. Right now, I'm okay with that. But I do know that I will have to really work at it consistently to keep my weight where it is.
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