Genetic Link to Alcoholism and Obesity: A New Study in Molecular Psychiatry

[Monique]

Chroot, you need to be more sensitive to the issue. There is genetic variablity that will cause some people to be more sensitive to weight gain than others. In current western societies the brake has been set loose by the over-abundance of food (among other things), so that we are seeing an outbreak of obesity. The study that was mentioned at the start of the thread indicates the fact that some people are at a higher risk for gaining weight, as others are at a lower risk. As said, if a defect in a gene causes you to have a bad self-image or some other psychological effect, it is not difficult to imagine how that would result in obesity in the current society.

You say: eating is the cause, the question is: what causes the overeating.

 

[chroot]

You say: eating is the cause, the question is: what causes the overeating.

"Most fat people are fat because they give into marketing, don't understand portion sizes, don't pay attention to calories, choose foods poorly, don't exercise, use food to cope with environmental stress, and choose to selectively forget about the 800 kcal worth of "light snacks" they consume everyday."

It's almost entirely a result of environment and behavior.

- Warren

 

[Monique]

And I agree, diet is the key. Give an obese person a stomach-bypass and they are going to loose half their weight. I often wonder: why don't they eat less instead of having such drastic surgery and living a life without proper food.

Don't you think that there are groups of people who are prone to over-eating? Or prone to poor food-choice? Some people never have to exercise or pay attention to their food habits and they stay thin all their lives. What makes these people different, why does one group grab food and the other group leave food alone.

 

[selfAdjoint]

If we're going to account for the sudden increase in obesity, we need to focus on things that have changted, arguably since the baby boom generation grew up (they don't seem themselves to be part of the spurt).

Just a suggestion, based on only a couple of observations, but see what you think. Pediatricians have been recommending later and later times for introducing solid foods to new babies. The time now used by many (after six months of age) overlaps with a period of rapid cognitive development in the youndster. It is possible that having this wonderful new mouth experience at an age when it can be better appreciated has a causal effect on later eating behavior.

 

[chroot]

I agree that some groups are prone to over-eating, Monique, just like I agree that some groups are prone to alcoholism, and some groups are prone to smoking.

The difference, at least in US society, is that some level of self-control is expected of both alcoholics and smokers. Society expects alcoholics and smokers to accept responsibility for their poor choices.

If you choose to smoke, you won't be permitted to dine in many public restaurants, or you will face confrontations with coworkers. You will have to accept paying double or triple the premium for life insurance. You will have to accept enormous voluntary taxes for your cigarettes. The majority of voters feel that smokers deserve these social consequences for making the choice to smoke.

However, the US is incredibly -- almost hypocritically -- politically correct with respect to fat people. We're supposed to tiptoe around fat people to avoid hurting their feelings. Fat people don't have to pay more for health insurance, though they rightly should, since their healthcare is drastically more expensive. Fat people exert collective bargaining pressure to force airlines to offer bigger seats, yet not charge them anymore for the privilege of using them.

For some reason, Americans treat every other vice -- gambling, smoking, drinking, sex with prostitutes, you name it -- as being subject to both self-control and organized social consequences. For some reason, however, Americans seem completely unwilling to collectively accept that being fat is just as much a choice as participating in any of those other vices.

- Warren

 

[selfAdjoint]

Warren, the stated reason, at least for forbidding smoking in many places is the concern over second hand smoke. Whether this concern is well taken or not, it is a powerful political force. Similarly the restrictions on drinking are driven by a concern over drunk driving. By contrast there is not even the ghost of an issue over "secondhand fat" or "driving fat". As far as the public seems to be concerned, fat people are just doing it to themselves, and as long as we don't have publlic health care for Type II diabetes, it isn't seen as harming others, even in their wallets.

 

[Monique]

I agree that some groups are prone to over-eating, Monique, just like I agree that some groups are prone to alcoholism, and some groups are prone to smoking.

Ok, good.

My argument boils down to the notion that people are sentient, capable of reason and arithmetic, and should have higher-level control over their behavior, well beyond the simple stimulus-response model.

You give the human race way too much credit. There are many historical events that would disprove that logical (think Nazis and the German reich?).

I think it boils down to education. Take the people who are at a high risk of loosing control of their eating habits and coach them, teach them what normal eating habits are and what will lead them to gain a lot of weight (before they become obese). Insurance companies should take a lead in this, since it will save them a lot of money in the end.

 

[wolram]

There is a simple solution, give (fat) people jobs that make their bulk a hinderance ,and make their pay production related.

 

[Curious3141]

Not having actually had a person poking you in the posterior with a needle for half your waking hours, you are really in no position to make comparisons between the severity of being poked by a needle and your own hunger.

...Do you really not see your own hypocrisy?

My alleged hypocrisy (purely your opinion) is nothing compared to your obvious callous insensitivity.

Obviously, the physical fact is that, even while dieting, you continued to eat just as many calories as before, and that's why dieting didn't work. You probably believe many of the same rationalizations that other fat people choose to believe: I'm fat, and there's nothing at all I can do about it. Dieting just doesn't help!

Knowing nothing about me, you are in no position to make these assumptions. But then, you seem to be quite happy doing that about every overweight person out there, why should I be treated any more fairly, hmm?

Your adherence to those kinds of comforting falsehoods explains your aggressive posturing, too. You have fought long and hard to distance yourself from any personal accountability for your own weight. Here's a hint: hire a nutritionist full-time to monitor and record all your food intake for a week or two. Or end up bedridden and have a doctor put you on a gastric bypass diet. Guess what? You'll lose weight incredibly quickly. Your weight problem is not your body's fault.

More trite "psychoanalysis". Post up a scan of your MD and/or Psych degrees, you sure seem to be speaking with all the smug conviction of an experienced professional.

Happily.

http://www.ncbi.nlm.nih.gov/entrez/...uids=16210723&query_hl=21&itool=pubmed_docsum
​

Physical activity. Nothing to do with eating too much (whether that's due to satiety factors or "choice"). Quit with the straw men, I was specifically challenging your specious assertion on food intake.

http://www.cdc.gov/nccdphp/dnpa/obesity/contributing_factors.htm#Genetics

Fair enough. The article simply reiterates the prevailing view that obesity is a multifactorial disorder. A view which I completely agree with.

In other words, eating too much and exercising too little are the dominant reasons why fat people are fat.

REALLY? Show me exactly where the article used the word "dominant". The article merely stated that both genes and behavioral factors are at play. You have no right to quote scientific literature and then distort it wilfully to prove your own point(s).

Sure, there may be some genetic predisposition to obesity, just like there is for alcoholism. On the other hand, your genes don't actually make you fat. Your eating and exercise habits are the cause. You just need to learn to accept that.

Cancer has a strong genetic component, but it is clear that many cancers would not result without an accompanying environmental insult. Tell me, would you be lecturing a cancer sufferer with the same tone you've used throughout this thread? Or does your bigotry only extend to the overweight?

Alcoholism has a very similar disease profile to chronic obesity, yet acoholics are generally willing to acknowledge that nothing more than their own actions are what led to their condition. Sure, they may have a genetic predisposition, and that may lend them some comfort, but very few are content to just throw up their hands, kill themselves with alcohol, and say "I can't help being an alcoholic! It's in my genes!"

"Generally"? Where are you getting all these insights from? I have seen many online support groups that correctly acknowledge a genetic predisposition.

And I never once stated that it was OK to "give up" simply because of the indisputable genetic component these diseases (both alcoholism and obesity). I believe it is still important to fight natural urges with reason and willpower, and I fully intend to try another major effort in the near future.

What is NOT acceptable is for insensitive people like you to throw about callous opinions that fat people are weak and only too willing to play the victim, etc. A truly rational and impartial person (which you, with astounding hypocrisy, *claim* to be) would not be taking the tone you've taken throughout this thread. It's obvious you have a deeply held personal prejudice against overweight people. This is borne out by the fact that you brought up the example of fat people demanding larger seats on airplanes. Now this point was completely out of left field and has no possible relevance to a discussion on the genetics of obesity, *yet* you chose to bring it up, and that is very telling of a prejudiced person.

For the record I disagree with the view that an overweight person has the right to demand a bigger seat on an airplane. But I have no sympathy for a person who uses that sort of complaint as fuel for the fire of prejudice against ALL fat people.

Despite that fact that so many hurt feelings and sensitive social issues are wrapped up in our obesity epidemic, it does not chance the scientific facts. I am being truly impartial here -- I am simply repeating the unequivocal, honest truth: most fat people are fat because they allow themselves to be fat. Your desperate need to defer accountability for your own actions is not relevant to me.

- Warren

Please, quit your prejudiced posturing and stop trying to pass off your own opinions as "unequivocal, honest truth". It is unbecoming of a good scientist and good human being.

 

[Gelsamel Epsilon]

I have to say chroot that he is right. You must have had some bad experience with obese people in the past blaming their genes or something because so far all this thread has said is that genes can give you predisposition towards eating. Noone here so far has blamed their genes and no one has said that being fat is entirely genetic so I don't even know who you're arguing towards.

Even the link you posted and things you've said "Sure, there may be some genetic predisposition to obesity, just like there is for alcoholism." coincide with the opinions posted by other people here (being that obesity is not only genetic but environmental as well). It seems as though you're arguing with yourself (or maybe towards a bad experience with an obese person you know in RL or something?).

~Gelsamel

 

[chroot]

Like I said, Gelsamel Epsilon, I'm tired of fat people trying to garner sympathy from everyone else from their condition. I'm tired of having to tip-toe around the feelings of fat people. Our society doesn't encourage us to tip-toe around the feelings of gambling addicts or people who have sex with prostitutes, so why should we tip-toe around the feelings of people who voluntarily choose to become fat?

And, yes, I know what you're going to say -- they didn't choose to be fat -- but, in my opinion, they did. As I've said, we live in a world of nutrition labels and 24 hour gymnasiums. At least in my opinion, there's no excuse. For the vast majority of fat people, being fat is a choice.

- Warren

 

[russ_watters]

And I agree, diet is the key. Give an obese person a stomach-bypass and they are going to loose half their weight. I often wonder: why don't they eat less instead of having such drastic surgery and living a life without proper food.

I'm sure you know how simple the answer to that question is: it is hard.

I agree with chroot's general point here, though I would characterize it a little differently: people have interventions for gambling addicts and alcoholics. They are supportive when a friend tries to quit smoking. But you can't even acknowledge that someone has a weight problem. Behavioral or environmental, it is unPC to even say "I'm worried about you - you need to lose some weight. It isn't healthy". Say that to most smokers and some will say "I know" and others will say "I know, but I don't care".

Part of the problem is that there is a definite line with some problems where it is easy to identify a problem. With weight, the line is a moving target. Some people are clearly on one side of it, though, and do need a kick in the ass by a friend, plus a little more self-esteem/self-control (they really do go together).

The solution isn't an easy one, but it needs to be that people who are overweight have to accept that it is a bad thing and something worth trying to fix - regardless of whether it is entirely their fault or not.

Beyond that, though, people have different body types. I have the "Bart Simpson" body (small arms, big gut) and I work very hard to change that. Judging by how my dad looks at 60, I don't think it'll ever be a serious health concern, but if nothing else, I like looking and feeling better about myself when I'm in better shape. The point is that while everyone is dealt a different hand, you can always affect the outcome of the game.

 

[Gelsamel Epsilon]

Like I said, Gelsamel Epsilon, I'm tired of fat people trying to garner sympathy from everyone else from their condition. I'm tired of having to tip-toe around the feelings of fat people. Our society doesn't encourage us to tip-toe around the feelings of gambling addicts or people who have sex with prostitutes, so why should we tip-toe around the feelings of people who voluntarily choose to become fat?

And, yes, I know what you're going to say -- they didn't choose to be fat -- but, in my opinion, they did. As I've said, we live in a world of nutrition labels and 24 hour gymnasiums. At least in my opinion, there's no excuse. For the vast majority of fat people, being fat is a choice.

- Warren

Unfortunately that isn't what I'm going to say. They did choose to be fat because they were the ones that chose to eat. And neither am I saying that we should "tip-toe" around the feelings of fat people, what I'm saying, and what I think everyone else is saying in this thread - is basically that the obesity phenotype is genetically and enviromentally determined.

I'll use myself as an example. I do not exercise - I seriously sit on the computer all day. I also eat like a freakin' horse. But - despite me doing all the wrong things I am not fat. I'm 180cm (approx, havn't measured in a while) at 80kgs (again approx because I couldn't be bothered to measure in a while). But in no way am I overweight (I am definitely not fit though). This is because my metabolism is really awesome - and I posit that my metabolism's awesomeness is a consequence of my genes. This highly suggests that the weight of a subject is genetically and enviromentally determined.

~Gelsamel

 

[Moonbear]

Like I said, Gelsamel Epsilon, I'm tired of fat people trying to garner sympathy from everyone else from their condition. I'm tired of having to tip-toe around the feelings of fat people. Our society doesn't encourage us to tip-toe around the feelings of gambling addicts or people who have sex with prostitutes, so why should we tip-toe around the feelings of people who voluntarily choose to become fat?

And, yes, I know what you're going to say -- they didn't choose to be fat -- but, in my opinion, they did. As I've said, we live in a world of nutrition labels and 24 hour gymnasiums. At least in my opinion, there's no excuse. For the vast majority of fat people, being fat is a choice.

- Warren

Chroot, with all due respect, I'm going to step in here and ask you to please start sticking to the science and not to your own personal feelings and opinions. It may not account for all obesity, but there are quite a lot of recent studies out suggesting it really ISN'T as simple as you seem to think it is. Just rejecting the science without even reading up on it because of your own gut feeling is not at all helpful here.

Studies of defects in production of fairly recently discovered hormones and their receptors, such as leptin, adiponectin, and melanin concentrating hormone, are providing better insight as to why people really can't easily stop overeating. When you lack the signals that indicate satiety, or the brain doesn't have the receptors to respond to those signals, it's not just a matter of saying, "I'm full, no thanks," to additional food, because you never feel full.

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16941272&query_hl=3&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16941049&query_hl=3&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16935329&query_hl=3&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16926531&query_hl=3&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16926246&query_hl=3&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...uids=16782141&query_hl=12&itool=pubmed_docsum

Not only do these hormones influence satiety mechanisms, but there is also evidence from pair-feeding studies that they alter metabolism and fat deposition even if calories are restricted.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=16733553

http://www.ncbi.nlm.nih.gov/entrez/...uids=14636173&query_hl=22&itool=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...uids=11834436&query_hl=22&itool=pubmed_DocSum

http://www.ncbi.nlm.nih.gov/entrez/..._uids=8643697&query_hl=22&itool=pubmed_DocSum

 

[chroot]

Studies of defects in production of fairly recently discovered hormones and their receptors, such as leptin, adiponectin, and melanin concentrating hormone, are providing better insight as to why people really can't easily stop overeating. When you lack the signals that indicate satiety, or the brain doesn't have the receptors to respond to those signals, it's not just a matter of saying, "I'm full, no thanks," to additional food, because you never feel full.

As I said, that's where nutrtion labels come in. If you can't trust your satiety stimulus, you can always read the label and trust your brain.

Besides, do you know what percentage of obese people actually have a verified endocrin problem?

- Warren

 

[Reality_Patrol]

.. It may not account for all obesity, but there are quite a lot of recent studies out suggesting it really ISN'T as simple as you seem to think it is...Studies of defects in production of fairly recently discovered hormones and their receptors, such as leptin, ...When you lack the signals that indicate satiety, or the brain doesn't have the receptors to respond to those signals, it's not just a matter of saying, "I'm full, no thanks," to additional food, because you never feel full...

Moonbear, I'm disappointed in you. What a great discussion to drop in our favorite topic of photoperiodism and it's proven relationship to weight regulation in animals. Must everything be definitive before being able to be discussed here in your view?

For those interested: photoperiodism is the physiological process that regulates body rhythms (sleep/wake cycles, etc...). It's been shown to govern appetite/body mass changes as well through it's influence on setting circannual (seasonal) rhythms. It is an inherited trait, but reacts to changing environmental variables. In other words environment dictates the genetic response, not the other way around. In this sense, food supply is a secondary, if not tertiary, environmental variable.

 

[bross7]

I don't think that there is anything wrong with what was stated. There definitely seems to be heritability in terms of general body structure. But overall saying if you are fat = you have genes for being fat would be wrong.

There are far too many people who will use the genetic excuse, and it most likely will come from the ones who really don't have that as the reason they are fat.

 

[selfAdjoint]

I have a question for you biology mavens. Suppose someone consumes, say, 4000 calories of glucose and water in a day, and nothing else except oxygen from breathing. Can the body use these materials to build fat? Can you make fat molecules out of water, oxygen, and glucose? Can the body's metabolism do it?

 

[Monique]

It's called de novo lipogenesis, and it's anabolism not metabolism.

 

[Curious3141]

It's called de novo lipogenesis, and it's anabolism not metabolism.

Actually, anabolism is a proper subset of metabolism. The complementary subset being catabolism.

 

[Monique]

You're right

 

[selfAdjoint]

So, terminology apart, it can be done? Water, oxygen and glucose into fat?

I know the chemical pathways are probably beyond me (I googled before I asked - didn't get a clear answer). But that is what I'm really asking about; the body really can create fat (I guess fatty acid) molecules out of those precursers alone?

 

[Gelsamel Epsilon]

http://en.wikipedia.org/wiki/Lipogenesis

 

[Curious3141]

So, terminology apart, it can be done? Water, oxygen and glucose into fat?

I know the chemical pathways are probably beyond me (I googled before I asked - didn't get a clear answer). But that is what I'm really asking about; the body really can create fat (I guess fatty acid) molecules out of those precursers alone?

Most commonly, "fat" in the context of the human body refers to neutral fats, which are triglycerides (triacylglycerol). So we have to account for one molecule of glycerol (3C) and three molecules of fatty acids (which can have varying carbon chain lengths).

Very simplistically,

First glycolysis,

1) Glucose (6C) --> 2 Glycerol (3C)

2) Glucose (6C) --> 2 Pyruvate (3C)

3) Pyruvate (3C) + Coenzyme A (CoA) --> Acetyl (2C)-CoA + CO2 (1C)

Then fatty acid synthesis :

4) n AcetylCoA --> Fatty acid (2n C)

Then triglyceride synthesis :

5) Glycerol + 3 Fatty acid --> Triacylglycerol

 

[Monique]

So, terminology apart, it can be done? Water, oxygen and glucose into fat?

It's not terminology, I gave you the answer. The pathway is de novo lipogenesis that turns excessive carbohydrates into fat. But I don't think this is a significant pathway. The body rather uses carbohydrates for energy than fat, so with an excessive intake of carbohydrates your body will start to metabolize those and stores your dietary intake of fat for later use.

 

[Renge Ishyo]

Well, genetic disposition to eat or not, the fact of the matter is that one cannot become obese unless they have access to the food that makes them so. Even if it becomes proven fact that the tendency towards obesity is in some way strengthened by the function (or lack therof) of certain genes that control metabolism, fat cell generation, hormone secretions or whatnot you'd still have to admit that ultimately the food a person eats is at least partly responsible for their final condition. How many obese people do you see in some of the poorer nations, like India or Africa? Not too many, regardless of what genetic predispositions they may or may not have (ultimately, you can't get fat without the food!).

In the USA you see all sorts of freakish new diet related diseases such as diabetes affecting more and more people these days. Someone might analyze the situation and present a paper saying "Oh, these people seem to have some genetic defect that prevents the proper levels of insulin production". They might be right scientifically, but this doesn't take into account the possibility that the *cause* for something like type II diabetes is poor diet over the course of several several years. What if the same can be said for people who are later found to have "genetic dispositions towards obesity?" The question I have is, were they really born with it or did these isolated "genetic defects" develop after 10-15 years of neglect...

 

[Gelsamel Epsilon]

It's true, that you can't get fat if you don't have the food. But some people can't get fat if they don't have the genes. Take me for example, I happen to be lucky enough to eat all I want and I never put on weight! This is the whole point of the Genetic-environmental model of phenotypes. Sure you can say "without the food they won't get fat" but you can't say "food is therefore the soul cause of obesity" because there are other factors. This is in no way a scapegoat to blame something on something obese people can't control this is a way to understand obesity better so you can better treat it.

 

[Renge Ishyo]

I don't even understand what this debate was about anyways. Even if the link to genes becomes proven fact, it's not like we can treat it by mutating someone's DNA. It still comes down to treating it by making better choices when it comes to diet and exercising since those are the only potential causes that anybody can do anything about.

Epsilon, I was a garbage disposal when I was in my early 20's. Now, I so much as look at a piece of cheesecake and I gain 4 lbs...I guess this is just the way it is with most people when they get older and their metabolism slows down (of course now I can blame it on my faulty genetics instead of my age ).