Slashdot Mirror
MIT Researchers Discover "Metabolic Master Switch" To Control Obesity
New submitter ahbond writes: The meme of the chubby nerd alone in the basement may be a thing of the past. Well, at least the chubby part, if recent work at MIT pans out and we're able to use a biological "master switch" to "dial-in" a persons metabolic rate. “Obesity has traditionally been seen as the result of an imbalance between the amount of food we eat and how much we exercise, but this view ignores the contribution of genetics to each individual’s metabolism,” said senior author Manolis Kellis, a professor of computer science and a member of MIT’s Computer Science and Artificial Intelligence Laboratory and of the Broad Institute.
Where do I sign up to try?
Due to a new technique called "CRISPR-Cas9", there's been a whole lot of rapid development on the gene-identification front, and likely to be an explosion of new ones in coming months/years.
It's definitely being used here: Linky.
Likely lots of half/false leads will also come out of all this too, but thanks to all this, we're getting a lot further into exploring the whole nature/nurture beyond simple debating points, and I think it's all amazing and interesting.
Ryan Fenton
It isn't being ignored; it's part of the equation, and always has been. Metabolic rate acts as a multiplier on the "calories out" part of the equation.
To say metabolic rates don't vary significantly is simply wrong. In my own case I eat 3-4000 calories per day with nil exercise. I retain my lean figure despite everything I do to work against that outcome. It is true that just about any obese person could become healthier with less intake of food, but BMR remains an important factor.
Running an engine faster shortens it useful life,hmm, maybe this might not be a good idea. Will turning up the biological clock shorten up the life based around the clock. What is really solved by tweaking your system so that you can eat more junk food, damn, I just imagined the junk food companies incorporating this chemical into the pseudo foods they produce, they would go nuts with it.
Chaos - everything, everywhere, everywhen
BMR (basal metabolic rate) really doesn't vary much person to person.
Actually, the article is stating precisely the opposite. It states that the BMR is controlled by IRX3 and IRX5, and that this varies from person to person, and thus people have different propensities for fat storage as a result of the state of those genes. They went on to modify the nucleotide in mice, and demonstrated that they had in fact found the regulatory mechanism for the metabolic pathway.
Soooo... Fat people are fat because deserve to be fat... very scientific of you to call a constant something that actually is a variable.
I know many strength trainers, dieticians, and physical therapists that would disagree with you. BMR can vary widely from person to person, whether healthy or sick, and especially between genders. There are tons of medical conditions that will actually mess with BMR as a side effect, as well as definite genetic problems. BMR also changes with age, and various age related conditions. Contrary to the gospel you just tried to spew out, all of these is being researched and tested on a wide variety of populations.
If this research is correct, "what you use" does change if this gene is expressed. So while the x/y equation might not change, both the values of x and y can.
Why is parent modded down? He made a good point, one that most people have seen with their own eyes.
Next door to me lives a sixty-year old man who is rail thin despite living the good life (especially with food) and never exercising. I'm not talking about merely not overweight, this guy is really skinny. His twenty-something daughter is already pretty hefty, not fat yet but will be by the time she's thirty. Same lifestyle, half of the same genes, different results.
You could be right, but would you actually be upset if you were wrong about this?
Part of the issue for people trying to lose weight is that their metabolism slows down to avoid burning calories. The body doesn't like giving up calories that it has already stored, and when it has to do so, it basically figures that times are tough, and it doesn't know when they're going to be good again... so it reduces the metabolic rate, and increases storage of excess calories when they do come in. It's thought that this effect may be permanent, but even if it's not, it is certainly a long lasting one, and it's one of the reasons that, even years after losing a large amount of weight, people have a hard time keeping it off (and most fail). Being able to re-tune ones metabolic rate would help overweight and obese people immensely in not only taking that weight off, but keeping it off in the long run. (Of course, this all ties back into the microbiome in the gut as well. The real takeaway from all the new research into obesity is hardly surprising: The human body is complex, and is extraordinarily good at storing and using energy in efficient ways. Modern diets are only about 10,000 years old, and the calorie rich eating of today is less than 100 years old. And our bodies are still evolved to run during boom and bust cycles, where even the boom cycles are pretty thin compared to the energy uptake/use ratios that the average person has daily.)
Why is parent modded down?
Because it is anecdotal. No matter how true it may be, it is terrible science.
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
Weird, because you clearly don't know when to stop making sounds out of it when you want to control stupidity.
"Old man yells at systemd"
This thermodynamics argument is oversimplifying things. The human body is not a perfect black box (ie. there is output), and all calories are not biologically processed the same way. Fructose has almost no use in the body whereas glucose is the main fuel, so 2000 calories from glucose will not trigger the same response as 2000 calories from fructose. Moreover, if the body was just consuming this magic "calories" unit, we could all run on electrical power...
The article is vague, but if you changed a person's metabolic rate (how many calories are burnt without exercises) you would also expect them to have a corresponding change in body temperature. Perhaps there's another explanation for IRX3 and IRX5 and obesity being linked. They mentioned "a complete resistance to a high-fat diet" which sounds like, it adjusts how these mice eat (and certainly doesn't mean the same thing as metabolic rate). Of course, saying you have a miracle obesity cure that means you don't need to change any of your life habits, all based on an experiment with mice, sells better.
Slashdot: providing anti-social weirdos a soapbox, since 1997.
I never said "deserve." I was a fat guy, and now I'm not a fat guy. I did it the same way everyone ultimately does it: eating less and moving more. There is some, but not much, person to person variation in BMR. You can calculate your own BMR to a reasonable accuracy using your age, mass, gender, and body composition. From there it becomes an engineering problem: energy in and energy out.
It's a simple problem, but not an easy one. The energy in part is extremely difficult to tackle. Hyperpalatable foods - foods with a combination of fats, salts, and simple carbs or sugars - are a huge problem. They are cheap and make it easy to eat far far more than one needs. It's very difficult to maintain the energy in side of the equation when we spend our days surrounded by calorie-dense, delicious food that is essentially free.
Satiety is strongly affected by hormones and genetics - some people can "eat whatever they want" and maintain their weight while some people can't. If you're really strict about observing these people (who often claim they eat 3000+ calories a day and don't exercise), they eat far less than they think they do. I've observed a number of those people, and counted calories on them. It never fails. The energy equation always wins. You can put someone on an isocaloric diet, measure their mass change over time, and calculate their average calorie expenditure.
Satiety is also strongly affected by the food you eat, which is why low-carb diets are often so effective. It's really rather difficult to eat 3000 calories worth of meat and vegetables a day, while 3000 is no problem when you include bread, chips, ice cream, soda, juice, etc.
On top of that, our society is getting fatter and fatter. It's not because BMR is changing.
tl;dr Variability in BMR from person to person can be explained almost entirely by the known predictors (gender, age, height, fat mass, and fat free mass), and the obesity epidemic is not caused by differences in BMR.
Satiety is strongly affected by hormones and genetics - some people can "eat whatever they want" and maintain their weight while some people can't. If you're really strict about observing these people (who often claim they eat 3000+ calories a day and don't exercise), they eat far less than they think they do. I've observed a number of those people, and counted calories on them. It never fails.
And I've done the same and found the opposite. They actually burn far more calories at rest than BMR would suggest. The basic metabolic rate of people varies largely.
the obesity epidemic is not caused by differences in BMR.
Nobody ever said it was. Seems you are ignoring all the science, so you can support your personal opinion about the obesity epidemic. Processed food changes the content of the food. This causes obesity by triggering over-eating in those who aren't eating things required by their body. If you are iron deficient, you'll have cravings. Often for iron-rich food. If your food has the useful contents purged from it, it'll cause over-eating. It's not a "willpower" thing. It's a malnutrition thing. We are eating the bare minimum to not be malnutritioned, and it's making us fat, because the food doesn't have food in it anymore, just flavor. That's what's causing the obesity epidemic.
Learn to love Alaska
If I wasn't so depressed about being an American, I wouldn't be eating all these cheetos while watching British sitcoms trying to find some form of light in my shallow excessive existence.
Suborbital [spaceflight] is the special olympics of spaceflight. - Rei
The Hacker's Diet hits all the main points.
"First they came for the slanderers and i said nothing."
Original paper, New England Journal of Medicine
http://www.nejm.org/doi/pdf/10...
The article is vague, but if you changed a person's metabolic rate (how many calories are burnt without exercises) you would also expect them to have a corresponding change in body temperature.
This is precisely what they found.
I've made another posting (later) in which I link to a PDF of the original research paper, if you care to read it.
Not true. A single data point can invalidate a theory. It just can't "prove" anything.
But invalidate, yes.
while (sig==sig) sig=!sig;
It's possible his body isn't absorbing all those calories and instead is ejecting them as waste.
Or I suppose he might be a mutant with strange muscle and energy usage.
Or he has some sort of parasite in him.
This is flat out wrong. The whole point of a regression is to determine the correlation in noisy data. We're not talking about random points here like paint thrown at a piece of graph paper, but rather a correlation between indep. variables vs. dep. variables which have a distribution. That in no way negates the possibility that the mean values of the samples can be tightly correlated to the indep. vars.
Now what might be the physical basis for high variance in basal metabolism vs. low variance? Well, there are about a zillion parameters in the human body with complex interactions, genetic & epigenetic dependencies, etc. that we barely understand! Yet we assume that everyone is the same?
I'll tell you where this unscientific belief comes from--the "soul" model of human consciousness. Most discussions of obesity have a heavy bias toward the view that people simply choose to be pigs. Evidence that this is false is steadily accumulating, as it is clear that simply turning a few knobs on your hormone regulation, or other parameters, could turn you into a completely different person--an obese compulsive eater, a drug addict, etc. Note that it is easier to perturb a well optimized body so as to degrade health and behavioral regulation vs. bringing one from non-optimum to optimum.
No. Not all calories are burned. There is caloric intake, but there is also metabolic efficiency, which can vary with diet, and probably also with individual characteristics.
You have cause and effect reversed. You are going to eat more if you are gaining weight. We understand this relationship correctly when children are growing, when women are pregnant, and when we breed some cattle to be thin and produce milk while others are bred to be heavy so we can harvest more meat off of them.
In evolutionary terms, we eat when we are hungry. We certainly are not the offspring of organisms that failed to observe this simple rule. Those organisms are dead, and if they had any offspring, the offspring are dead too.
And don't forget that people tend to gain or lose weight after poop transplants, tending usually towards the donor's BMI.
There is more, if you care to go do some research. Science is poking holes in the "fat people are lazy and/or stupid" myth almost daily now.
See that "Preview" button?
No, parent is modded down because a bunch of fat hate ppls swarm around all these stories and downvote. Make no mistake, parent isn't modded down- he's downvoted.
Spend half your money on coke, the other half on drugs to avoid gaining weight, what a life!
Funny, so many developers/coders here, and yet they forget ye old addage 'garbage in, garbage out', or another way, if input > output, guess what happens?
So many people want excuses (it's my genes, it's my metabolism, I'm big boned, blah blah fucking blah). For the VAST majority of people, it's simple, they consume more calories than they burn.... period.
I dropped 30 lbs after keeping a food log for 6 months -- you know what I found, I was initially eating more than I should be, shocker I know! I reduced my calories from ~ 2200 a day to ~1600 and what do you know, I lost about 1-1.5 lb a week every week. It's THAT simple for 99% of the population, why is it everyone claims they're the 1% who have a thyroid or metabolic issue, when they know they're fat cause they fucking eat too much?
People want a pill or quick fix for everything... or an excuse
'The unexamined life is not worth living' - Socrates
Your BMR may still be 2000, you just aren't absorbing all 3-4000 calories that you eat. In other words your intestines are crappy and you're pooping out half your calories. :)
Gut bacteria play a huge role in how much nutrition/calories we absorb from our food.
That quote was from a computer scientist. If energy in > energy out you will get obese. Genetics isn't going to magically create the fat for you, nor does it magically make exercise take no energy to perform, it just contributes to how big or small the right side of the balance is going to be.
I think part of the problem is even if you say have two people with the same hunger "drive" and they manage to eat the "right balanced diet" for that caloric level there is no guarantee that your desire to eat is going to match your bodies ability to burn that which you eat. So for example, people with this disease might have to live a life where they are always a bit hungry, or walk their asses off every day in order to force themselves to balance out. Anyways, there are many factors that go into obesity, but at some level it is a disease and like someone with asthma or liver failure it means your lifestyle might not be able to be the same as the next guys, or even the way you prefer. I don't like it that I need to workout 4-5 days a week to keep my body weight stable, but that is what I have to do because I have a slow metabolism and prefer exercise over eating very small portions (for me at least normal meal + exercise leaves me less hungry than taking the equivalent calories out of my meals instead, + it has nice side effects like benching 300lbs and a resting heart rate of 52).
Part of the problem is diet and exercise take time. A lot of other medical conditions don't really take that long each day to deal with, you take your pill, carry your inhaler in case you need it etc, but proper diet and exercise means you are probably spending an hour a day making food (or the equivalent hours working to pay for it prepared for you) and another hour or so being active (maybe more if you go to a gym and then need a second shower on workout days) which you might not be lucky enough to get from your work either. It can easily eat up 15 hours a week.
Servants to reduce their physical workload? Yes.
Cooks to prepare food with little effort? Yes.
One day's labor or income providing more than 10 days of food? Yes.
Plenty of food all winter? Yes.
Children somewhere else for much of the day? Yes.
Sugar is a _result_ of wealth and modern industry supported by that wealth. I'm afraid it's hardly the only factor modern obese people share with historically obese people.
Anytime somebody is biased towards their pet it-looks-good-on-paper-and-I-want-it-to-be-true theory, and feels the need to deny actual real word experience, they trot this "anecdotal" rebuttal. In a few cases, it's a valid rebuttal, but it's incredibly overused here.
Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.