Another thing to blame your parents for
July 29, 2013 3:33 PM   Subscribe

A layperson-friendly analysis of a seminal (1100+ cites) study on obesity that found no correlation between environment/upbringing and obesity, whilst finding very strong correlation between genetic heritage and obesity. To sum up: adopted children's body weight matches their biological parents, not their adoptive parents.
posted by seanmpuckett (64 comments total) 23 users marked this as a favorite
 
I know the Stunkard study is 27 years old, but I wanted to share the recent explanation of it. And, despite its age and repute, there still seems to be a lot of noise in the thought sphere still blaming upbringing or parenting habits or bad food for obesity.
posted by seanmpuckett at 3:37 PM on July 29, 2013 [1 favorite]


This is really interesting, thank you.

I noticed that the study was conducted in Denmark. In terms of the effects of environment, I did wonder if the results would be similar if it was replicated in a country with either a higher obesity rate and/or more inequality.
posted by jb at 3:42 PM on July 29, 2013 [3 favorites]


This recent post about our microbiome and the possible (likely) role of gut flora in our health was also fascinating, and only serves to emphasize how little we really know about the human metabolism.

What we do know is that it isn't as simple as calories-in, calories-out, and never has been.
posted by rtha at 3:43 PM on July 29, 2013 [10 favorites]


Perhaps some genotypes are more sensitive to the recent increase in superstimuli.
posted by Human Flesh at 3:45 PM on July 29, 2013 [2 favorites]


I think this study shows that genetics is a very large factor in obesity. But Denmark is a country with relatively low rates of obesity as well as public health care and low inequality. There may be lifestyle factors - like quality of food or commuting times - which were shared by both biological and adoptive families.
posted by jb at 3:46 PM on July 29, 2013 [6 favorites]


I foresee loads of kids telling that certain sibling "See! You ARE adopted!".
posted by King Sky Prawn at 3:48 PM on July 29, 2013 [3 favorites]


So, trying to ask a real question here but I might bungle it a little bit - what about the disparity between certain countries and the rise in the frequency of obesity esp. in the US?

It seems like if the tendency towards obesity is heritable, the US should reflect the obesity levels of much of the world, since we're rather a hodgepodge. But we lead the world in numbers and extremity of the condition. Why is this? It's not like we are a destination for people with a predisposition towards obesity. The world is getting fatter, and we are ahead of them. Genes obviously play a major part, but it seems pretty clear that bad diet and habits, as typified (apparently) by Americans, is also important.

I notice MoonOrb brings up the same question in a different way.
posted by BlackLeotardFront at 4:00 PM on July 29, 2013 [2 favorites]


I guess predisposed genetics is the primary influencer, followed by poor quality diet/lifestyle? And if you have the trifecta, you lose the weight battle?
posted by panaceanot at 4:04 PM on July 29, 2013 [2 favorites]


I bet that diets in 1980s Denmark were pretty homogenous across the population, at least compared with the differences you'd find between Western and non-Western countries. What the study says is that there was no correlation between family environment and obesity, not that there was no correlation with the broader environment. And I don't think it excludes the possibility that in societies more diverse than Denmark was 30 years ago you would see significant differences between families as well.
posted by A Thousand Baited Hooks at 4:22 PM on July 29, 2013


What we do know is that it isn't as simple as calories-in, calories-out, and never has been.


I think I understand what you mean, but I never understood why people phrase it that way. True, there are factors that influence satiety, hunger, and macronutrient bioavailability, but that doesn't change the fact that an energy surplus is required to synthesise tissue.
posted by Human Flesh at 4:24 PM on July 29, 2013 [6 favorites]


What we do know is that it isn't as simple as calories-in, calories-out, and never has been.

This is simply not true.

More than one peer reviewed study has determined that from October 1982 through March 1984 that human weight was determined specifically and only by calories-in, calories-out.
posted by flarbuse at 4:24 PM on July 29, 2013 [5 favorites]


It seems like if the tendency towards obesity is heritable, the US should reflect the obesity levels of much of the world, since we're rather a hodgepodge. But we lead the world in numbers and extremity of the condition. Why is this?

It appears that epigenetics and in utero conditions have a large influence. In other words, the environment/upbringing of your parents appears to have a strong effect on your predisposition to obesity.

Ahh, is there anything we can't blame our parents for?
posted by Durin's Bane at 4:28 PM on July 29, 2013 [3 favorites]


Wasn't there a study recently that suggested weight tended to vary quite significantly with the average weight of your coworkers? That is, people who went to work at an office where everyone was thin tended to become thin themselves and vice versa. It seems a little hard, at least superficially, to reconcile that with this finding.
posted by yoink at 4:40 PM on July 29, 2013 [1 favorite]


I also found it hard to square with studies of people who migrated to different cultures--like Japanese people who settled in the US or other Western countries, and ended up fatter on average than people who remained in Japan.

...

But Denmark is a country with relatively low rates of obesity as well as public health care and low inequality. There may be lifestyle factors - like quality of food or commuting times - which were shared by both biological and adoptive families.

I think it's safe to assume that some of the genetic component here is not just stuff like your metabolism but also inherited behaviors and habits. In other words, some people are genetically predisposed towards eating more of the wrong things when the opportunity presents itself. Also, genetics can define how people respond physically to different environments. So certain people may be worse at processing certain kinds of foods, for instance.
posted by Edgewise at 4:44 PM on July 29, 2013 [2 favorites]


More than one peer reviewed study has determined that from October 1982 through March 1984 that human weight was determined specifically and only by calories-in, calories-out.

The human body is not a bomb calorimiter. It doesn't set the food you eat on fire and magically apportion fat.
posted by Slap*Happy at 4:48 PM on July 29, 2013 [3 favorites]


The human body is not a bomb calorimiter

But surely within some degree of exactitude it more or less is, no? That is, if we take humans and put them in cages with exercise wheels and feeding tubes and we consistently give them fewer calories in food than they expend in total energy, they will lose weight, no? And if we consistently give them more calories in food than they expend in total energy, they will gain weight, no? I mean, sure, there's a margin of fuzziness there, but it's not as if there's some magic you can do whereby as long as all the food is blue then you gain weight on half the caloric input or lose it on double the caloric input.

Are there any laboratory controlled studies of people gaining significant quantities of weight on a calory-restricted diet or vice versa (setting aside cases of disease etc.)?
posted by yoink at 5:03 PM on July 29, 2013 [1 favorite]


yoink, I think the problem with your question is that the real world often isn't a laboratory controlled setting. I doubt public health officials think that draconian laws dictating calorie intake would be an appropriate response to the rise in worldwide obesity rates. I'm guessing that most studies on obesity are concerned with causes that can be (but often aren't) addressed at the institutional level. Social economic status pops up a lot as a factor as does urban/rural inequality, television watching, car use, cross-national norms, and so on and so forth.

At the individual level, calorie-in, calorie-out is more mantra then truth. There is no actual utility in that statement besides external shaming or internal motivation. It's a reductive hypothesis that relies on grade school biology and ignores the complexities of everyday life.
posted by dubusadus at 5:33 PM on July 29, 2013 [5 favorites]


Yeah, "a calorie is a calorie" is a deeply annoying false truism. John Kiefer has the short version:
The Idea: Given two diets identical in calorie count, the two must produce the same weight loss or gain regardless of macronutrient content.

The Logic: By the 1st law of thermodynamics that says energy is neither created or destroyed, must, somehow, say that 100 calories of carbohydrates will produce identical effects as 100 calories of fat — or protein for that matter.

The Reality: The idea that a calorie is a calorie actually violates the laws of physics and contradicts several well-controlled studies; you can manipulate macronutrients to cause weight-loss even while increasing calories.
I removed the citations, but he's got 'em if you click through to the long version.

Rob Dunn blogged another excellent takedown of the tired calorie-is-a-calorie oversimplification at Scientific American. Here's just one small excerpt:
In a paper published recently in the Proceedings of the National Academy of the Sciences, Rachel Carmody and collaborators at Harvard University examined the effect of the two most ancient forms of food processing–cooking and grinding (technically in their study, pounding)–on the calories available in those same foods.

Carmody knew from her previous work that starches like those in sweet potatoes have more of their calories available to digestion the more they are cooked (at least to a point). As a result, no two sweet potatoes you cook will ever have the exact same number of calories because they grew differently and because you will have cooked them slightly differently. But what, Carmody wondered, about meat? Meat is relatively easily digested; its calories might be just as available in sushi as in a McDonald’s hamburger. Surely, meat is just meat, the one thing that our estimates of calories get right. Wrong.
Click through to the full post for the citations in link form.

It's trivially and uselessly true that ceterus paribus, restricting calories will reduce the amount of energy coming into the human system and therefore cause weight loss. But ceterus is never paribus when it comes to food! Even ignoring the differences between people, a single person's gut biota changes, the foods they eat change, their macronutrient ratios change, their willingness to engage in strenuous activity or casual exercise changes.

"A calorie is a calorie" is true only to the extent that it is deeply reductive. For the most part, it is misleading.

As for the study itself, I always raise the fact that BMI is suboptimal for any study about obesity-qua-fatness. For instance, the layperson's summary of the study stated "BMI is the measurement of how much fat a person carries," which is patently false. I don't think it makes a big difference in forming conclusions from this particular study, but it's worth noting.
posted by daveliepmann at 5:37 PM on July 29, 2013 [19 favorites]


Yeah, I feel like people always want to take away the wrong message from this. It's not surprising that, at least in comfortable first world conditions, there is high heritability when it comes to things like obesity, but it's not like your genes are a death sentence. Controlling your weight really is as easy as controlling your calories. Ideally while you're at it you should control your muscle mass and general health through appropriate nutrition and exercise as well but weight is straight up calories. You may not be a bomb calorimeter but you still obey the laws of thermodynamics. If you eat at an energy deficit your body has to burn off mass in order to compensate and that's really all there is to it. The fact that genetics may change your basal metabolic rate by a couple hundred calories or so is unfortunate for some, fortunate for others, but it doesn't really change the way you should control your weight. The effect sizes also aren't as large as you might suppose. We're talking like a difference of maybe a couple hundred calories between two otherwise identical people.
posted by NathanBoy at 5:38 PM on July 29, 2013 [4 favorites]


yoink, I think the problem with your question is that the real world often isn't a laboratory controlled setting.

But the question of "is this useful advice or a useful fundamental model with which to approach personal choices about nutrition and exercise" is, surely, a very different one from the question "is this basically scientifically correct?" no? Decades of unhappy experience tell us that simplistic calorie counting models aren't very useful. But it is, nonetheless, true, is it not, that a higher caloric input than output leads to weight gain and a lower caloric input than output leads to weight loss? I mean, I'm not asserting this dogmatically; if you can point to a study of rigorously controlled input/output that shows this to be nonsense I would be entirely grateful. But my understanding is that whenever such studies have been tried, achieving weight loss was relatively trivial; where those studies failed was that the weight was regained pretty rapidly after the subjects ceased to be part of the experiment.
posted by yoink at 5:42 PM on July 29, 2013 [1 favorite]


No, yoink, because these studies are epidemiological in nature. They don't aim to affect decision making from the bottom-up like you're asking. I think people tend to draw personal inferences about the conclusions in these studies without realizing that these studies aren't controlled in that way. Their thrust is macroscopic. For example, this study in particular doesn't reach beyond the conclusion that genetics are more significant than upbringing as factors that cause obesity. For advice that you can take home you'd want to delve into cognitive or exercise science though my girlfriend tells me that her public health professors can get pretty snobby about the p-values those sciences consider to be acceptable. ;)
posted by dubusadus at 5:56 PM on July 29, 2013 [2 favorites]


Wait, seriously, I always thought the problem with "calories in calories out" was that it was only trivially true, that it didn't account for the non-lab setting of the real world, that one's calories in and calories out were the result of complex social and psychological factors that were the true root cause of weight gain.

Are we now saying that people can lose weight eating above maintenance? Can someone explain this?
posted by downing street memo at 5:57 PM on July 29, 2013 [2 favorites]


Rob Dunn blogged another excellent takedown of the tired calorie-is-a-calorie oversimplification at Scientific American.

I don't really see that this is either getting at the same point or ultimately all that significant. That is, the claim it's debunking is really just the claim that conventional calorie counts are accurate. So, it turns out that the body absorbs calories from cooked food better than calories from raw food, and gets fewer calories from almonds than a conventional calorie count would suggest. Jolly good. But all that requires is that we recalibrate our calorie counts. So many calories per oz for cooked potatos (on average), so many for raw (on average). Similarly, some people are marginally better at extracting caloric value than others; but these are pretty small effects. So, then, refine the calory count to more accurately state what calories are being genuinely made available to your lab subjects and all you do is narrow the margin of variability for the broad, general thermodynamic truth: calories in/calories out is the ratio that results in weight gain or weight loss, no?
posted by yoink at 5:59 PM on July 29, 2013 [3 favorites]


Controlling your weight really is as easy as controlling your calories.

This is absurdly untrue, grossly reductionist, and a complete failure to properly grapple with the scientific evidence or with the experiences of people attempting (and usually failing at) long term weight loss.
posted by misfish at 6:00 PM on July 29, 2013 [9 favorites]


They don't aim to affect decision making from the bottom-up like you're asking.

Er, that's not what I'm asking. I think you've got me backwards.
posted by yoink at 6:02 PM on July 29, 2013


Controlling your weight really is as easy as controlling your calories.

This is absurdly untrue


Well, surely it is absurdly untrue to suggest that it is "easy" (perhaps a truer statement would be "controlling your weight really is as hard as controlling your calories"), but surely that basic claim is far from being "untrue." Limit someone's caloric intake below maintenance and they will lose weight, won't they? Can you point to any studies that have suggested otherwise?
posted by yoink at 6:05 PM on July 29, 2013 [4 favorites]


It feels that it's not so much "easy" as it is "straightforward". Knowing what the steps are is easy; doing them is obviously not. It's tempting to write that off as 'willpower' but that's too simple to be true.
posted by Skorgu at 6:15 PM on July 29, 2013 [1 favorite]


I also found it hard to square with studies of people who migrated to different cultures--like Japanese people who settled in the US or other Western countries, and ended up fatter on average than people who remained in Japan.

Think of it like drug sensitivity. Let's say a particular gene determines whether you're sensitive to drug X (i.e., whether you develop disease X' on exposure). If you have the "sensitive" version of the gene but never see drug X, there's no obvious difference between you and your neighbors. You might even be healthier than they are. But you move to a place where drug X is in the water and all of a sudden boom, you're sick with disease X'. So in the new place, the heritability of susceptibility to disease X' is very high. Real world's more complicated and a lot less binary, but that's the basic idea - there's a difference in the environment that exposes a genetic difference that would have otherwise been masked.
posted by en forme de poire at 6:29 PM on July 29, 2013 [5 favorites]


If I've got you backwards, yoink, then that means you're being pedantic. Unless you're ultimately trying to make some point about privilege and modernized society's access to food, I have no idea why you're arguing semantics about calories-in, calories-out as an underlying principle. Yes, ultimately, people who are malnourished will tend to not be overweight or obese. What's your point?
posted by dubusadus at 6:33 PM on July 29, 2013


These adopted child studies shed some pretty chilling insights on behaviors and qualities of different ethnicities. Honestly I'm not sure we're ready to hear them yet.
posted by Halogenhat at 6:35 PM on July 29, 2013


> "Are we now saying that people can lose weight eating above maintenance? Can someone explain this?"

If you poop out the food faster than your body can process the calories, sure.

Personally, I discovered that I can lose weight (at least in the short-term) eating nothing but thousands of calories/day in ice cream because large amounts of ice cream gives me diarrhea.
posted by Jacqueline at 6:38 PM on July 29, 2013 [3 favorites]


So this isn't really at all applicable to anything other than 1980's Danes, right?

I don't mean to dismiss the post, but is there any reason to imagine that the results apply at all anywhere else?
posted by graphnerd at 6:41 PM on July 29, 2013


Presumably, Danes have things in common with other humans.
posted by Human Flesh at 6:43 PM on July 29, 2013


Limit someone's caloric intake below maintenance and they will lose weight, won't they?

Well, they might get sick or die before they get to a "normal" weight, as unfortunately it's not guaranteed that you'll just lose fat when you drop calories. For instance, you could lose cardiac tissue (and indeed, obese people have died on very low calorie diets, mostly from heart failure).
posted by en forme de poire at 6:57 PM on July 29, 2013 [6 favorites]


Are we now saying that people can lose weight eating above maintenance?

Well, trivially, sure: just make your metabolism totally inefficient using an uncoupling agent. (Warning: do not attempt.)
posted by en forme de poire at 7:07 PM on July 29, 2013 [3 favorites]


Surely it's clear in context that when people are saying "calories in" they mean "calories absorbed into the body's energetic system", not "calories put into the mouth", right?

My understanding of "eat less, move more" as a weight loss mantra is "eat less than you did, move more than you did" not "eat less than someone else, move more than someone else", which would seem to cancel out many of these points about relative efficiency in extracting energy from portion Y of food X.
posted by curious.jp at 7:32 PM on July 29, 2013 [5 favorites]


en forme de poire: (Warning: do not attempt.)

"The factor that limits ever-increasing doses of DNP is not a lack of ATP energy production, but rather an excessive rise in body temperature due to the heat produced during uncoupling. Accordingly, DNP overdose will cause fatal hyperthermia. [...] Fatal overdoses are rare, but are still reported on occasion. These include cases of [...] suicide, [...]."

Good lord. What a way to go out.
posted by curious.jp at 7:35 PM on July 29, 2013


Yeah, uncoupling agents are scary shit.

To back up, I think the issue is that saying that the human body obeys mass balance doesn't mean that much in practical terms. If this were really all you needed to know, then the best dieting strategy would be to just fast completely until you hit your target weight. Some doctors do indeed use total fasting or very low calorie diets to treat obese patients, but they have them on heart and blood monitors the entire time because there can be serious side effects. That alone indicates that you need to worry about more than mass balance in the treatment of obesity.

The second law is also not so relevant to the epidemiology of obesity. The modern increase in obesity is clearly only partly due to an increase in food availability, because there are a lot of lean and medium-weight people, who are not dieting, even in a very "obesogenic" environment. So what are the factors that make them different? I can guarantee you it's not access to the information that calories in = calories out, or an abundance of willpower or whatever. So maybe we can learn something about the most effective ways to treat obesity from studying these differences, since whatever we're doing right now is clearly not working very well at the macro level.

(And of course, there are practical issues with maintaining long-term caloric restriction and even measuring caloric input accurately, as others have mentioned -- etc., etc.)
posted by en forme de poire at 7:57 PM on July 29, 2013 [4 favorites]


Limit someone's caloric intake below maintenance and they will lose weight, won't they?

up to a certain point, I guess this is technically true, but I'm guessing that two people with different genetic makeup can eat the same diet and it will have different effects on their bodies. Me and my friend Dave are roughly the same height and age, and me at my most fit and healthy clocks in at about 15 pounds heavier than him at his lazy junk food eating worst. And most people would look at him and still register him as "thin, but maybe needs to get some exercise" and me as "big guy, kinda soft around the middle" For him to eat his way up to the top of my weight range or me to the bottom of his would probably kill us both.

But as I found out when a health scare forced me to drastically modify my diet, If you want to get to the heart of whatever is going on with weight in our society, processed food is the culprit. I now can't eat a good 90% of the food in the grocery store and the difference it has made in my life is astounding. The scariest part is (and maybe this is just me, but I doubt it) giving up processed foods cold turkey leads to actual withdrawal like symptoms. And after a few weeks certain cravings and desires about food that I previously accepted as innate just went away. Willpower isn't even really necessary.

I'm firmly convinced that anyone who can eat an average American supermarket/prepared food diet and not gain weight is just lucky. But maybe "lucky" is the wrong word. My oldest stepbrother, who never paid attention to what he ate because he never gained weight, ended up diabetic.

Any study of modern Obesity that doesn't start with bulldozing the fast food joints and barricading the supermarket aisles is not really serious about solving the problem.
posted by billyfleetwood at 8:13 PM on July 29, 2013 [14 favorites]


The main reason "calories in, calories out" does not work is because of ATP. I am not very good a biology, and the insanity of the naming scheme for most of the metabolic processes makes my head hurt, but if you want to understand the human (and pretty much all carbon based life) metabolism, you need to understand how "food" (i.e. calories in) becomes "energy" (calories out).

It is not a simple process, nor is it a simple "burn calorie, get energy". In fact, one of the fascinating things about the whole ATP cycle is just how much energy can be utilized (and re-utilized) over and over again through many different cells throughout the body.

You also have to look at just what the energy storage process is, and how it really is a kind of add-on insanity that wasn't really designed to be used infrequently. In order to get the energy out of fat cells, there is a whole series of chemical reactions that need to be triggered before the body can even think of utilizing those stores. Of course, it's not even really a thought process, more of a biochemical response to stress. And that is another factor that totally messes with the whole process.

Did you know that you can maintain the exact same caloric intake that "should" keep you at a maintenance weight, yet you will still gain fat? In fact, you can even reduce our caloric intake and still gain weight. That's because certain stresses cause the body to horde calories as fat, because certain stress hormones (cortisol being one of the primary ones) trigger your metabolism into a hording mode? And you have absolute no control over this process. You can't tell your body "hey, we need to get rid of some of this fat, switch to fat burning mode". Your body never reads any memos your conscious tries to send it.

The whole thing runs on autopilot, too. Kind of neat, if you think about it, but also something you have to be aware that you can't directly control.

You also have to consider what the purpose of stored fat is, as well.
Our modern 1st world life is so far removed from our pre-agrarian ancestors. Now, my direct knowledge of this is fuzzy, at best, so bear with me as I kind of drop tropes in here in lieu of actual historical context. Our metabolic system is evolved from hunter/gatherer type homonids. Our closest cousins, bonobos, still survive in the wild with this type of diet. The main difference between how we eat today, versus how our closest genetic cousins eat? We eat every day. And I mean every single day, we eat. Monkeys? It's a lot of feast or famine. Some days, they will get to eat all day, for several days in a row. And then that food source is gone, so they have to go find more. And then they can go for several days to a few weeks (I'm not sure on this, but bear with me) before their next real meal. That whole time, without new food, they don't just keel over and die (neither do humans, but the way some people talk, go a few hours without eating something and they'll wither up and die), but instead their bodies process all those stored calories from fat, and live off of that. Does their weight fluctuate? Absolutely, sometimes wildly, I'd imagine. Now, our bodies could do the same thing (and they do). We just aren't used to it. One of the main things that civilization brought with it was stability, and with that stability, the expectation of not being hungry. But that is a conscious rationalization. At heart, our bodies don't care whether we feel pretty. It just cares about whether we have enough fuel to get to the next fuel source to load up on more fuel, because fuel is what keeps our cellular processes going.

And the mitochondria? Man, those are some nasty task-masters, only interested in keeping the exchange of energy between cells going. Like nasty energy bankers, who only care if energy is moving in or out of a cell, and taking their toll for every transaction.

If you ask me, it's all the mitochondria fault for this whole "life" thing. They're probably interdimensional stock traders or something.
posted by daq at 9:16 PM on July 29, 2013 [5 favorites]


A fairly simple example of why calorie in/calorie out doesn't work very well is that the amount of time that food spends in the small intestine determines how many calories (nutrients) are extracted from it.

Fiber is normally passed right on through with relatively little extracted. Meat on the other hand is slowed to a crawl while every little bit is taken. Eat that same fiber with your meat and it's going to be stuck in the small intestine for a lot longer than it would otherwise.

The first half of The Second Brain provides an amazingly good description of this, along with the rest of the enteric nervous system. Can't recommend it enough.

Which reminds me, a good place to point people who are perhaps a bit too reductionist about the gastrointestinal tract is the Complexity section of the Wikipedia article for the enteric nervous system. There is a reason there is a whole field of study dedicated to it.
posted by Tell Me No Lies at 9:44 PM on July 29, 2013 [3 favorites]


A layperson-friendly analysis of a seminal (1100+ cites) study on obesity that found no correlation between environment/upbringing and obesity

This phrasing incorrectly elides an important distinction made (as I understand it) in Stunkard et al. They find that there is no correlation between obesity and "family environment". This is a specific term and does not necessarily include factors of the built environment, toxicological factors, local food systems/cultures, and other factors that come perhaps most readily to mind when we talk about obesogenic environments.

(For disclosure, my understanding is based on the short analysis linked in the OP, not on the source paper.)
posted by threeants at 11:12 PM on July 29, 2013 [5 favorites]


threeants just made an extremely important point.
posted by Salamander at 11:14 PM on July 29, 2013


I don't mean to dismiss the post, but is there any reason to imagine that the results apply at all anywhere else?

I think the point is just that it shows heredity is a significant factor. Even if, in non-Danish environments its influence may be obscured by other factors, that's still something we would want to know.
posted by Segundus at 12:58 AM on July 30, 2013


"It's not as simple as calories in, calories out" is a useful phrase because it's ambiguous.

People within the fat acceptance movement often believe in a strong version of "set point theory":
Set point theory suggests that our body has a particular range of weight that it is comfortable in, usually about 10% of a body’s weight. That means, if you weight 175, you have about an 18 pound range; if you weigh 325, you have about a 33 pound range. Most people lose and gain within this set point on a pretty regular basis. They may put on a little weight in the winter and lose it in the spring. Or get busy and drop a little weight. Or gain a little when stressed. Or lose a little during an illness. Or whatever. Movement within this range is normal. However, movement outside of that range is not. In fact the body seeks homeostasis – that is the body seeks to stay within that range. To move outside of that range something must go on, something must happen to the body...

...When something tries to change the weight of an individual, the body fights back. This is true of both up and down. In the Vermot Prison study (1964) when researchers overfed prisoners, they found that the prisoners gained about 15%-25% of their body weight, then their metabolism shifted so that they could gain no more.
In its extreme form, believers in "set point theory" believe that it doesn't matter whether you eat 1,000 calories a day or 5,000 calories a day: your weight is controlled by your "set point" not by the amount of calories you eat.

The slogan "It's not as simple as calories in, calories out" functions as a kind of dog whistle in fat politics. True believers can understand it to refer to "set point theory". Non-believers tend to think it refers to the more mainstream and scientifically accepted effects of genes, exercise, starvation and biological mechanisms on metabolic rates.
posted by TheophileEscargot at 1:24 AM on July 30, 2013 [2 favorites]


Human Flesh wrote: Presumably, Danes have things in common with other humans.

Look, you might think that but in fact ...
We feel restless, we feel blue,
We feel lonely, and in brief,
We feel every kind of feeling
But the feeling of relief
We feel hungry as the wolf felt
When he met Red Hiding-hood
What don't we feel? We don't feel good!

There is nothing like a Dane! Nothing in the world! There is nothing you can name that is anything like a Dane!
posted by Joe in Australia at 1:29 AM on July 30, 2013 [2 favorites]


Take three groups:

One takes 3000 calories of fat a day.
One takes 3000 calories of protein a day.
One takes 3000 calroies of carbs a day.

The three groups will not, in fact, experience identical metabolic effects. Calories in, calories out is actually an oversimplification, as most declarations from biology tend to be.

We are simply not optimized for simplicity.
posted by effugas at 3:02 AM on July 30, 2013 [1 favorite]


Just a single point of anecdata. My sibling and I are both adopted by the same family and both at a very early age, both ate the same family meals and snacks, both lived a very similar lifestyle. From the get-go, very different body types and BMI. They couldn't put it on, I couldn't take it off.

It is quite a fascinating business, being one of two adoptees. It makes one chary of simplifications - in fact, of a great deal of the nature/nurture business.

Whatever you think they are, people ain't like that.
posted by Devonian at 3:28 AM on July 30, 2013 [1 favorite]


Wasn't there a study recently that suggested weight tended to vary quite significantly with the average weight of your coworkers? That is, people who went to work at an office where everyone was thin tended to become thin themselves and vice versa.

YES! I'm bringing down every office I'm in! Screw you and your January diet fads!

(Now I just need to get a job at a fashion mag or something like that...)
posted by Katemonkey at 3:41 AM on July 30, 2013


A lot of people talk about heritability as 'how genetic' a trait is, but that's not really it. Heritability is the proportion of variance due to genetic factors, and that's an important distinction. If the environment changes, the heritability changes (even in relatively homogenous Denmark).
posted by motorcycles are jets at 6:26 AM on July 30, 2013 [5 favorites]


I love how "calories in/calories out" is obviously shorthand for:

'Calories in, calories out' is well-known shorthand for 'weight loss is this easy, and if you're fat, it's because you're a lazy idiot.'

And likewise disagreeing with it is obviously shorthand for:

In its extreme form, believers in "set point theory" believe that it doesn't matter whether you eat 1,000 calories a day or 5,000 calories a day: your weight is controlled by your "set point" not by the amount of calories you eat.

Instead of any of the billion more reasonable positions that could be taken in between those positions. Both can be false as-stated and yet have elements of truth.

If every time someone says 'calories in/calories out' you replace that with 'weight loss is easy' you're (IMO) willfully ignoring physics.

Likewise if you substitute the inverse with "weight loss is not in any way connected to how much people eat".

So how about this:
  • Weight loss isn't magic but it is complicated and hard. Modifying the amount and quality of calories you ingest and the amount and effectiveness of your activity is sufficient to change your weight (that's what I think most people actually mean by calories in/calories out).
  • Actually making that change is really hard, you've trained your body to expect a certain amount of a certain type of food to maintain your current body size before becoming full (what the set point really is, again IMO). You're not just adjusting your weight you're slowly trying to move that set point down to whatever level you're aiming for.
  • To do this is going to require large, structural changes in lifestyle that may be much more difficult for some than others because of socioeconomic factors as well as genetics, the body shape of your friends and family, and thousands of other reasons (again, what I think the take-home for the epidemiological studies is).
It's not as snappy as code words, dog whistles and incoherent rage I admit.
posted by Skorgu at 7:23 AM on July 30, 2013 [3 favorites]


Mod note: Folks, dial this back and don't make it into a referendum on one people's opinions and quit calling each other names. Don't make this thread into a "we can't do this well" self-fulfilling prophesy.
posted by jessamyn (staff) at 8:08 AM on July 30, 2013 [2 favorites]


Moreover, I'm curious to know upon what basis the paper in question be deemed "seminal." Other than the number of times it's been cited (which I don't personally have the knowledge to properly put in context), is the study a well-known, -discussed, or -respected one in medicine or public health? Honest question; I have no idea and I'm hoping someone can chime in. It's not really clear to me that this work has broad implications in a generally useful way, which I don't necessarily imagine is what the scientists involved were aiming for, anyway-- I'm more than willing to believe that it's a very conscientious treatment of the specific subject matter it deals with.
posted by threeants at 8:47 AM on July 30, 2013


It's easy enough to prove that weight loss is more complicated than calories in < calories out. We can very easily determine this by watching "calories in" as it approaches zero. More or less you will see immediate weight loss in the form of water loss, then slower loss in the form of fat loss, which then slows down and you start seeing muscle loss at an even slower rate. (If you keep going, you start seeing weight loss by bacterial decomposition which is clearly outside the scope of this discussion.)
posted by Karmakaze at 9:03 AM on July 30, 2013


My understanding of epigenetics is lay-level but it is really interesting if you think about it. When you are conceived, you are the product of your father's sperm and your mother's egg. The sperm was made recently, probably no more than a month ago. But your egg was made when your mother was an embryo two or three decades earlier.

So not only do you have to contend with the environmental conditions under which you were conceived -- for your father's sperm and your gestation inside your mother -- but also the conditions under which your mother was conceived.

I've been fighting my weight all my life, and though when I was conceived there wasn't a food shortage (my parents were in the US Navy), when my mother was conceived it was 1943 during WW2 food rationing in the US, so nutrients would have been scarce.

Interestingly, my mother's older brothers, conceived before rationing, all had children (my cousins!) who do not have trouble with weight. The brothers (and my mother), though, do/did have weight trouble, and as it happens their mother was born in 1914. I don't know if she was often hungry, but at the time the family were sharecropping so they certainly weren't flush (there was no rationing during WW1).

It's really interesting, though, thinking about how this stuff dances through the generations.

I wonder what the obesity stats are on people who's grandmothers were born during the lean years of WW2.
posted by seanmpuckett at 9:27 AM on July 30, 2013 [1 favorite]


From Greg Nog's excellent link -
"over the past 20 years or more, as the American people were getting fatter, so were America’s marmosets. As were laboratory macaques, chimpanzees, vervet monkeys and mice, as well as domestic dogs, domestic cats, and domestic and feral rats from both rural and urban areas. In fact, the researchers examined records on those eight species and found that average weight for every one had increased...
More:
In fact, lab animals’ lives are so precisely watched and measured that the researchers can rule out accidental human influence: records show those creatures gained weight over decades without any significant change in their diet or activities."
Wow. If that's not a smoking gun for environmental or epidemiological factors at work, I don't know what would be.
posted by Slap*Happy at 9:28 AM on July 30, 2013 [3 favorites]


As far as I can see from Google, the finding that lab animals are getting fatter comes from a single study, by David Allison of the University of Alabama at Birmingham, published in Proceedings of the Royal Society B.

It seems like a perfectly respectable paper, but it's still just a single study. It's got a tremendous amount of media attention, and is regularly trumpeted as evidence that Something Mysterious is Going On. But there are other explanations:
Jaap Seidell, a nutrition and health researcher at the VU University Medical Center in Amsterdam who has studied the link between weight gain in pets and their owners, contends that the data presented in the study could be explained by lifestyle factors.

"This is an interesting collection of data, but it's very difficult to interpret them," Seidell says. Pets and feral animals might very well be subject to changes in our eating patterns, and there isn't enough information to conclude that the captive animals are exempt from such influences, he adds. Other factors may also have changed. For example, over the past 30 years the number of rodents housed in each cage may have altered -- which could very well affect the amount of exercise they get.
posted by TheophileEscargot at 9:38 AM on July 30, 2013 [1 favorite]


Also, from the comments, lab animal chow has not necessarily changed in terms of macronutrients but it has been reformulated over the years. Which of course is also interesting, if true.
posted by en forme de poire at 9:41 AM on July 30, 2013


Significant long-term weight loss is generally very difficult, but it isn't complicated. Yes, there are a number of factors that complicate how many calories you actually extract from food, and how many you expend. However, when you combine serious diet and exercise, it's pretty much impossible to avoid losing weight. If you're exercising with purpose, you have to be spending a fair number of calories, and metabolic compensation can only lower expenditure so much. Restricting caloric intake likewise sets a ceiling on the number of calories that you can extract from food. The only way to avoid losing weight in this scenario is by expiring if your body can't get enough energy to maintain basic functions, but that's pretty unlikely unless you're in really poor health or you're exercising way too hard.

None of this contradicts the basic premise of the article. Good/poor lifestyle habits, willpower, etc. are probably very much tied to genetics, at least where food is involved. Of course, maybe my genetics say that I'm going to get into amazing shape at age 40, and I'll never know unless I try :) Speaking of which, I've lost 35 pounds in the last 2.5 months using serious exercise and significant caloric restriction.
posted by Edgewise at 1:33 PM on July 30, 2013 [2 favorites]


I doubt anyone discussing obesity in good faith would say that obesity has nothing to do whatsoever with genetics. Clearly obesity is medically and culturally complex. Great, but...what's the policy takeaway from the genetic angle? Whatever the "amount" of obesity is that's determined by the environment, our human environments seem a heck of a lot more pliable than our genetics, no? Personally, I'm not some sort of anti-obesity crusader per se; I'm a big fan of Health at any Size. But I can't think of a single obesity-targeting environmental intervention that doesn't also have the wider effect of fostering better health for all people, whether sickly "normal" weight folks, fit fat folks, or whomever.
posted by threeants at 1:59 PM on July 30, 2013 [1 favorite]


I'm pretty sure "fit fat folks" was the beginning to some horrible vocal warm-up from high school drama class that I've long stowed away in the cobwebs of my brain
posted by threeants at 2:02 PM on July 30, 2013


But I can't think of a single obesity-targeting environmental intervention that doesn't also have the wider effect of fostering better health for all people, whether sickly "normal" weight folks, fit fat folks, or whomever.

I think it's a very common misconception, in this thread, that this study is saying that environment doesn't matter. It really isn't saying that. What it's actually suggesting is that upbringing doesn't matter, and genetics do. Besides, genetics interact with the environment, expressing phenotype differently depending on external conditions. A few other people in this thread seem to be trying to clear up this confusion, but I'm not sure if everyone is getting it. So there is nothing to suggest that environmental changes will not have a big impact.
posted by Edgewise at 2:41 PM on July 30, 2013


I really think that the focus on obesity is hugely misguided both for public policy and for individual health. It's true that obesity is related to ill health, but it isn't always true that weight loss is a necessary or sufficient intervention for addressing obesity related ill health.

When we're trying to become healthier, we shouldn't be focused on the easy symptom of how fat you are, but on the factors that more directly address our health status, such as blood pressure, cardio-vascular fitness, cholesterol levels, etc.

If your relevant numbers are good, it doesn't actually matter if you are still fat. If they are not, it is not relevant that other people can count your ribs.
posted by misfish at 6:31 PM on July 30, 2013


"This is an interesting collection of data, but it's very difficult to interpret them," Seidell says. Pets and feral animals might very well be subject to changes in our eating patterns, and there isn't enough information to conclude that the captive animals are exempt from such influences, he adds. Other factors may also have changed. For example, over the past 30 years the number of rodents housed in each cage may have altered -- which could very well affect the amount of exercise they get.
Considering that every effort is generally made to maintain uniform conditions for lab animals precisely so longitudinal studies will be possible, this kind of criticism holds little water in the absence of actual information showing how conditions were in fact different.

taz linked to the abstract of the original article in a fascinating comment a few weeks ago, but the entire thing turns out to be free online and is well worth looking at.
posted by jamjam at 6:17 PM on August 1, 2013 [1 favorite]


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