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Excess insulin due to excess fructose is the cause of obesity in 90% of people, Robert Lustig, MD
Tuesday, March 06, 2012 11:20 am Email this article
"The question is, what is the biochemical force that is driving weight gain?" asks Robert Lustig, MD in this 15 minute video interview.
"Well, there are several, but, I would say that 90% of obese people have one [biochemical force that is driving weight gain]... Insulin," Lustig continues.
"Insulin is the energy-storage hormone."
"Insulin's job is to take whatever you're not burning and stored as fat."
Author Gary Taubes talks about the exact same thing in his book "Why We Get Fat".
Lustig says that he believes the increase in obesity in the past 25 years is mostly due to an increase in fructose consumption which causes insulin resistance, which raises insulin levels, which causes the body to convert more calories into fat, which makes people tired and hungry, and makes them fat.
Lustig says that the idea that people have gotten fatter due to a lack of will power is not correct.
Transcript of the Interview
Transcript of the 15-minute interview with Robert Lustig, MD
Here is the transcript of the 15-minute video interview with Robert Lustig, MD.
Telling People to Eat Less and Exercise More Has Set Us Back
Telling people that all they have to do is eat less and exercise more has set us back in the war on obesity
When asked about the idea that overweight people merely need to eat less and exercise more, Robert Lustig, MD says in this 15 minute video interview, “I think that [this message] is what has set us back so severely in this entire disaster [of increasing obesity] is this concept “Eat less, exercise more.”
First, people can’t eat less.
And people can’t exercise more.
The Message Blames the Patient
The message of telling people that all they have to do is eat less and exercise more is blaming the patient for their obesity
If you say eat less and exercise more, basically what you’re saying is, “It’s your fault.”
You’re putting the onus on the patient that it’s their fault, and basically you’re saying, “It’s your behavior that cause this,” which I don’t believe.
What causes obesity?
Obesity is a Problem of Fat Regulation
Prior to 1940, researchers knew that obesity is a problem of fat regulation
Prior to 1940, pretty much across the board, people recognized that obesity was a defect in fat deposition.
[Author Gary Taubes refers to it as a problem with fat regulation rather than fat deposition, but Lustig and Taubes are talking about the same thing.]
Two Ways to Interpret Why We Overeat and Get Fat
The first way: If you eat it, you’d better burn it or you will get fat
There are two ways to interpret the First law of thermodynamics [which says there is a conservation of energy.]
The first way is, if you eat it, you better burn it, or you’re going to store it.
[Calories in minus calories out equals weight change.]
[This is the] conventional [belief about the cause of obesity.]
And it’s done nothing [to slow the obesity epidemic].
There’s been no movement whatsoever anywhere in the world [in helping to reduce obesity] on that message, because it’s not correct.
The Second Interpretation
The second interpretation: We are driven to overeat by a biochemical force that is out of our control
The second way [to interpret the First law of thermodynamics], which I think makes much more sense, is if you’re going to store it, it is… caused by a biochemical force that is, essentially, out of your control.
We can talk about what those forces are.
And you expect to burn it, that is normal energy expenditure for a normal quality of life, because energy expenditure and quality of life are synonymous.
Then you have to eat it.
Gluttony and Sloth
Gluttony and sloth are a result of this biochemical force
The two behaviors that we associate with obesity… gluttony and… sloth are actually markers for the biochemical process rather than causes.
The question is, which comes first?
[The gluttony and sloth are] a result [of this biochemical process that causes obesity], not a cause.
What Is the Force Behind Gluttony and Sloth?
Excess insulin causes gluttony and sloth
The question is, what is the biochemical force that is driving weight gain?
Well, there are several, but, I would say that 90% of obese people have one [biochemical force that is driving weight gain]... Insulin.
Insulin Causes Calories to Be Stored as Fat
Insulin is the energy-storage hormone
Insulin is the energy-storage hormone.
Insulin’s job is to take whatever you’re not burning and stored as fat.
If you burn what you eat, and there is nothing to store, you don’t need much insulin.
If you don’t burn what you eat, then you need to store it, and insulin will go up very specifically to drive that energy into fat cells for storage.
Insulin shunts sugar to fat.
Insulin makes fat.
More Insulin Means More Fat
Higher insulin levels means you will be come fat in the long run
More insulin [means] more fat. Period.
If you have high insulin levels, then you will become obese in the long run?
It just so happens that when you say high insulin levels, you make it sound like that’s an easy thing to figure out.
[But] it’s not so easy.
There are Two Insulin Problems
There are 2 Insulin Problems: Insulin resistance and excess insulin secretion
There are two insulin… disorders.
There is one called insulin resistance which people know about.
[Metabolic syndrome, and type II diabetes are examples of this.]
It’s a sympathetic nerve-mediated phenomenon, and it’s primarily nerve and muscle.
The Second Insulin Problem
The Second Insulin Problem: Excess insulin secretion
And then there’s a second one called insulin hypersecretion which is not nearly as well known.
Most Doctors Don’t Test for Excess Insulin Secretion
Most doctors don’t test for excess insulin secretion, so they don’t realize their patients have it
You can’t see it on a fasting [blood sugar] specimen.
You have to stimulate [the pancreas to release insulin] to see it.
Most people don’t do those studies, so they can’t see it.
Children with Brain Tumors Removed Can Become Massively Obese
Children with brain tumors removed can become massively obese because their brains can’t see leptin which causes them to overeat
The quintessential patient who has this problem is the child who had a brain tumor [who had it surgically removed], and then becomes massively obese.
This is how I got into obesity 16 years ago, was taking care of these kids.
It’s called hypothalamic obesity [that is, it is the result of damage to the hypothalamus in the brain.]
This is a Window Into the Cause of Obesity
Although this is uncommon, it is a window into the cause of obesity
[It’s not very common], but it’s a window showing how the neuroendocrinology of energy balance works.
It turns out that the reason why these kids gained so much weight is because they have leptin resistance.
They Have Leptin Resistance
Leptin resistance makes them think they are starving all the time with leads to massive overeating
But they have organic leptin resistance.
Those neurons that normally [transmit] the leptin signal in the brain are dead.
Their brain sees starvation all the time…
[That’s very rare, but] the rest of the world suffers from functional leptin resistance.
So this hypothalamic obesity is really just a prototype for what’s going on in general obesity.
What Causes Leptin Resistance?
What causes leptin resistance? Excess insulin
The question is, if you don’t have a brain tumor and you are obese, why do you have leptin resistance?
What caused the leptin resistance?
Our work, and the work of many other people… leads to one answer, and one answer only… insulin.
Excess Insulin Causes Leptin Resistance Which Makes You Hungry
Excess insulin causes leptin resistance which makes you more hungry
Insulin promotes leptin resistance… and it makes you more hungry.
Insulin Resistance Predicts Food Intake
The more insulin resistant a person is, the more they will eat
There are numerous studies that show that the degree of insulin resistance predicts how much food people will eat at a… buffet.
This is work from Hahn and Yanofsky(?).
We’ve done work very similar to this as well.
Insulin Causes Satiety in the Short Run
Insulin causes satiety in the short run, but increases hunger in the long run
If you go to the literature, it says that insulin causes satiety, and that is true in the acute situation.
It is not true in a chronic situation.
And there the data is much less clear, but we have it, and it shows that insulin promotes further food intake.
Insulin Is A Major Causes of Obesity
Insulin is one of the major causes of obesity
Insulin is one of the main problems [causing obesity].
It is probably the primary main problem in the majority of [obese] people, and the question is, what made their insulin go up?
And what would you do about it?
First, you have to diagnose them.
18% of the Population Secretes Excess Insulin
18% of people secrete excess insulin which causes leptin resistance
About 18%, of the population has [insulin hypersecretion which causes leptin resistance].
They are releasing [too much] insulin…
Those patients can be treated with a drug that suppresses insulin release.
Very Low-Carbohydrate Diet
A very low-carbohydrate diet probably works best these people who secrete too much insulin
Or the other way that you can treat those patients is a very low-carbohydrate diet.
That might be the place where low-carb diets work the best.
Many Things Can Cause Excess Insulin Secretion
Glucocorticoids, other drugs, atypical antipsychotics and sedentary activity can cause the body to secrete too much insulin
However, if you don’t have insulin hypersecretion, and you have insulin resistance, the question is, what made you insulin resistant?
That’s a complicated issue, and there are probably many things that make you insulin resistant, for example, glucocorticoids, other drugs, atypical (antipsychotics)… and sedentary activity.
Fructose Causes Insulin Resistance
Fructose causes insulin resistance, and thus, excess insulin secretion
The big issue, worldwide, that causes insulin resistance is fructose… meaning sugar.
Because, what it does is cause liver insulin resistance specifically because of the way fructose is metabolized.
When you get liver insulin resistance, that causes your pancreas to have to make more [insulin]… which drives [calories] into fat.
Insulin Resistance Can Cause Many Diseases
Insulin resistance can cause cancer, diabetes, cognitive decline
And also, when your liver is insulin resistant, you get a lot of other diseases that go with it… diabetes, cancer, cognitive decline and a lot of other things.
Can drinking soda give you those diseases in the long run?
That data already exists.
Some Researchers Say Insulin Has Nothing to Do with Obesity
Insulin has everything to do with obesity despite what some may say
Some… researchers out there are saying insulin has nothing to do with obesity, but you are saying it is the most important thing?
I think it has everything to do with obesity.
Why do these people deny that insulin has nothing to do with obesity?
I think they’re steeped in a certain dogma that may have been [believed to be true] 10 years ago, but has clearly been overturned.
And they haven’t… [accepted] what is currently known.
Insulin Causes Satiety in the Short-Term
Insulin causes satiety in the short-term, but increases hunger in the long-term
Mike Schwartz at the University of Washington has said for [15 years] that insulin induces satiety… that insulin works like leptin, and in the acute situation… He’s absolutely correct.
I don’t does discount anything that Schwartz says about the acute effects of insulin… that’s all true.
In the middle of the meal, [you release insulin which tells your body] you don’t need to eat anymore, and so it is part of satiety.
I have no problem with that.
I mentored a graduate student who injected insulin [into the brain] which food intake stop [immediately], so I’m very clear on the acute effects of insulin on food intake.
That’s not what were talking about.
The Long-Term Effects of Insulin Are Very Different Than The Short-Term Effects
The chronic effects of all hormones is different than the short-term effects
What we are talking about is the chronic effect [of insulin].
Because chronic hyperinsulinemia is a very different animal.
In fact, every hormone that exists has a different acute effect then it does a chronic effect.
Insulin is no different.
Insulin Is Required To Store Fat
Insulin is required to store fat despite what some may say
The next thing is that many people say that you don’t need insulin to store fat.
Tell Type 1 diabetics that.
They say that’s a special case.
That’s not a special case.
What’s special about that?
I don’t buy that.
Protein Also Releases Insulin
Each patients should be analyzed to determine the best treatment for them
Another thing is that they say is that… it’s not just carbs that [cause] insulin release, but protein does it to, and in some cases even more, such as whey protein.
I think there are a lot of things that can cause insulin to go up.
Branched chain amino acids cause insulin to go up.
[Branched chain amino acids include leucine, isoleucine, and valine.]
It’s not just carbohydrates.
It’s not just fructose.
Fructose Intake Has Increased In The Past 25 Years Along With Obesity
Fructose intake has increased in the past 25 years along with and the increase in obesity
I think those are the big things that have increased globally in the last 25 years that coincide with the obesity epidemic, but I think there are a lot of things that could potentially do it [cause excess insulin release].
For any individual patient, you have to evaluate that patient, and see what’s going on, in direct therapy appropriately.
Diabetics Know Insulin Causes Weight Gain
Diabetics who take insulin know insulin causes weight gain; teenage diabetic girls often stop taking insulin to lose weight
As a physician, when I treat patients with insulin, they usually gain weight.
All the diabetics [who take insulin] are aware of it.
The female teenage diabetics omit their insulin shots… specifically to lose weight.
It’s a manifestation of an eating disorder.
They know [the insulin causes weight gain].
An Example of How Insulin Causes Gluttony, Sloth and Weight Gain
An example of how excess insulin causes gluttony, sloth and weight gain; insulin causes calories to go into fat, which increases hunger and fatigue, which leads to weight gain
The people who object to this… are saying that injecting insulin is different then normal physiological insulin production.
It has everything to do with it, and I’ll show you how.
Let’s take you, Andreas [the doctor doing the interview], your nice and thin.
Your Weight Is Stable on 2000 Calories Per Day
Your weight is stable on 2000 calories per day, but injecting insulin will increase fat storage, decrease your desire to exercise, increase your hunger, and make you fat
Let’s say you eat 2000 calories per day and burn 2000 calories per day.
You feel good.
Are you going to gain weight, lose weight, or stay the same?
You’re going to stay the same, right?
Right, because you burn what you eat, and nothing is stored.
Now, let’s do a little experiment.
I am going to put an IV in your arm…
I’m going to follow [you around], and every time you reach for food, I’m going to pump you full of extra insulin that you don’t want, and don’t need.
I’m going to over-insulinize you just like we do with our type 1 diabetics.
The Excess Insulin Cause 500 of 2000 Calories to Become Fat
This means you only have 1500 calories to burn, which makes you tired, hungry and fat
You wake up in the morning and you start out the day eating 2000 calories just like before, but now, because of the excess insulin… 500 of those 2000 [calories] go straight the fat.
You are now 500 calories heavier.
Now you only have 1500 calories to burn, but your body wants 2000 calories…
It’s called starvation.
The Excess Insulin Makes You Feel Tired Because You Don’t Have Enough Calories to Burn
This means you only have 1500 calories to burn, which make you tired, hungry and fat
How do you feel when you’re starved?
Crappy, tired, slothy, you sit on the couch, you don’t want to do anything, you don’t want to exercise… and, of course, you’re hungry.
So in a world of free access to food… what are you going to do?
You’re going to eat [those 500 calories that your body wants.]
So now you’re eating 2500 calories rather than 2000.
But I’m still pumping you full of insulin, so 100 of those 500 [additional] calories goes straight to fat.
The Excess Insulin Makes You 600 Calories Heavier Each Day
The excess insulin makes you 600 calories heavier each day which will make you fat in the long run
So now you’re 600 calories heavier, and you’re only up to 1900 calories to burn, so you still don’t feel great, so you go to a doctor and you say, “Doc, I don’t get it. Every time I get on the scale, I weigh more. How come I’m so fat?”
Your Doctor Tells You It’s Your Fault
Your Doctor tells you that your fat because you are a glutton and a sloth, not realizing that excess insulin is the cause of this
And the doctor tells you, “I know why you’re fat. Because you’re a glutton and a sloth.”
Because they’re looking at the… outcome of that biochemical process, not the cause.
The cause [of gluttony, sloth and weight gain was the excess insulin that I was pumping you full of], where is the outcome was a change in your behavior [increasing your calorie intake to make up for those calories that were lost to fat.]
The Problem Is The Result Of Too Much Insulin
The problem is the result of too much insulin, not because of glutton and sloth
The problem was [caused by] too much insulin, not gluttony and sloth.
Stop Drinking Soda
Stopping drinking soda would be a good start
So we should stop drinking soda?
That is a very good start.
Other Articles About Robert Lustig, MD
Other articles about Robert Lustig, MD posted here
Other articles about Robert Lustig, MD posted here:
Robert Lustig, MD
About Robert Lustig, MD
Robert H. Lustig, M.D. is a Professor of Clinical Pediatrics, in the Division of Endocrinology, and Director of the Weight Assessment for Teen and Child Health (WATCH) Program at the University of California, San Francisco.
More info about Dr. Lustig is posted here.
Robert Lustig, MD
University of California, San Francisco
513 Parnassus Avenue
San Francisco, CA 94143-0434
Campus Box 0434, S-679
Gary Taubes Says The Same Thing
Science journalist, Gary Taubes, says the same thing
The scientific journalist, Gary Taubes, says the same thing in his book “Why We Get Fat and What to Do About It”.
(I assume that Robert Lustig, MD learned about this from Taubes book.)
Here are links to some of the articles Taubes has written about this:
This is a MUST-READ Book
This is MUST-READ book for anyone interested in body weight
This is MUST-READ book for anyone interested in body weight… or anyone who believes that saturated fat is bad for you… or anyone who believes that carbohydrates are good for you… or anyone who believes that obesity is caused by a lack of will power… or anyone who believes that obesity is caused by eating too much and exercising too little (yes, of course this is true, but this does not answer the question as to why people eat too much and exercise too little, which Taubes answers in this book).
I highly recommend this book.
Gary Taubes is an excellent science journalist.
His previous books include “Good Calories, Bad Calories”, a longer book which is also about low-carb diets, but is a much longer book.Other Articles from This Book, Why We Get Fat
Articles from Gary Taubes current book, Why We Get Fat
Other Articles from Good Calories, Bad Calories
Articles about Gary Taubes previous book, Good Calories, Bad Calories
Contact info for Gary Taubes
Articles on the same subject can be found here:
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