PBS Interview with Gary Taubes

[Guest guest]

http://www.pbs.org/wgbh/pages/frontline/shows/diet

/interviews/taubes.html

 

Science journalist Gary Taubes wrote the controversial July 7, 2002

New York Times Magazine article, " What If It's All Been a Big Fat

Lie? " which turned the spotlight onto high-fat, low carbohydrate

diets. In this interview, Taubes explains his motivation for writing

his piece, the science behind the low-carbohydrate diet, and the

contention he faced when he published his findings. " I got crucified

in a variety of publications, " he says " ... It was fascinating. They

go after the messenger as much as the message. " He is currently

writing a book that is a historical and scientific exploration of the

hypothesis that weight gain and chronic disease are caused by excess

consumption of easily digestible and refined carbohydrates. This

interview was conducted Dec. 10, 2003.

 

What made you go after this topic in the first place?

 

Two things. I'd been reporting on salt and blood pressure, which is a

huge controversy, and some of the people involved in that were

involved in the advice to tell Americans to eat low-fat diets, and

they were terrible scientists. These were some of the worst scientists

I'd ever come across in my 20-odd year career of writing about

controversial science.

 

I literally called up my editor and said, " I just got off the phone

with so-and-so, and he's [taken] credit for getting Americans to eat

less eggs and less fat. This guy's one of the worst scientists I've

ever talked to, and if he was involved in this, then there's a story

there. " And that was it. I didn't know what the story was. I just knew

there was a story.

 

[Was there a personal motivation?]

 

Bfore I did it, I was up at MIT, interviewing an economist about

another story, a guy who runs a laboratory of financial engineering.

He told me about being on the Atkins diet, and how effective it was.

He was an Asian-American who had lost 40-50 pounds by giving up white

rice, in effect.

 

I thought I would try it as an experiment, since I was going to write

about fat and whether it really did cause heart disease and weight

loss. I tried it, and it was amazing. You know, it's everything -- the

20 pounds that I'd never been able to lose, in six weeks, and I

stopped exercising. It was kind of a surreal experience, and probably,

in a sense, informed my opinions from there on in. I mean, after that

happens, you say, " I want to know what's happening, and I want to know

why. "

 

 

 

Science journalist Gary Taubes wrote the controversial July 7, 2002

New York Times Magazine article, " What If It's All Been a Big Fat

Lie? " which turned the spotlight onto high-fat, low carbohydrate

diets. In this interview, Taubes explains his motivation for writing

his piece, the science behind the low-carbohydrate diet, and the

contention he faced when he published his findings. " I got crucified

in a variety of publications, " he says " ... It was fascinating. They

go after the messenger as much as the message. " He is currently

writing a book that is a historical and scientific exploration of the

hypothesis that weight gain and chronic disease are caused by excess

consumption of easily digestible and refined carbohydrates. This

interview was conducted Dec. 10, 2003.

 

 

Why is it so easy for us to believe that fat is a bad dietary

ingredient?

 

The idea is that fat has nine calories per gram, and carbohydrates and

protein have four calories per gram, and somehow the theory is that

the denser the calories, the more easier it is for us to eat more of

them. What happened is in the '50s and '60s, when researchers started

fingering fat as a cause of heart disease, the obesity researchers,

the obesity community started advocating low-fat diets, which they had

never done before. A low-fat diet is by definition a high-carbohydrate

diet.

 

But you had this sort of synchronicity where you had the heart disease

people saying, " Give up fat, saturated fat, for heart disease, " and

the obesity people started saying, " Give up fat because it must be the

best diet because fat is the densest calories. " They moved from there

without ever testing actually either of those hypotheses, so the

obesity people start recommending low-fat diets; the heart disease

people are recommending low-fat diets. They have actually no idea

whether it's going to cure heart disease, and the obesity people have

no idea whether these diets even work. But because they believe that

it's only the calories that [are] important, obviously if you give up

the major source of calories in the diet, you must lose weight.

 

You get this hypothesis that animal fats are the worst kind of fats.

That seems reasonable.

 

That came out of studies where you compare the fat consumption in

various countries versus the heart disease rates. Basically that's

what we still believe, that the Japanese have a very low fat

consumption. Greeks have very low animal fat consumption. They have

low heart disease rates. The U.S., Sweden, Finland have high fat

consumption, they have high heart disease rates, and that's the

genesis of that whole belief. " It's a worthless exercise, " is what one

researcher in the '50s called it. You cannot say that because fat

consumption associates with heart disease, that that means it causes

heart disease, because a lot of other things, for instance, associate

with fat consumption. Wealthy nations have a lot of fat. They eat a

lot of fat; they eat a lot of sugar; they get less exercise; they

smoke more cigarettes; they drive more cars; they have more

televisions.

 

There's a world of difference between the countries that eat low-fat

diets and the countries that eat high-fat diets. And to finger fat

because that's what you have in your mind to go in [to the study], is

just bad science. But that's what they did, and that's how animal fat

came out of it. We knew that animal fat, saturated fat, raised

cholesterol, LDL cholesterol, the bad cholesterol, and it was just

this sort of series of suppositions--

 

And we knew that cholesterol was associated--

 

And we knew that cholesterol was associated with heart disease. The

higher the cholesterol, the higher the heart-disease risk. Although

when you actually look at the studies, [it's] kind of amazing. If you

or I were to reduce our cholesterol levels by 30 milligrams per

deciliter, we would probably increase our chances of living an extra 2

years by one-thousandth of a percent or something. For the actual

individual who doesn't have extremely high cholesterol, lowering

cholesterol makes very little difference in how long you're going to

live.

 

There were several studies done in the late '80s, where they actually

calculated how much longer you would live if you cut back on saturated

fat. If everyone in the country cut back on saturated fat to that

recommended by the government, and cut back their total fat

consumption, you could then calculate from these studies how much

longer you would live. And the answer was a days to a few months. And

as the authors of this study pointed out, that was published in the

Journal of the American Medical Association, those are at the end of

your life. It's not like you get an extra month between 46 and 47.

It's, you're in the nursing home and you die at, say, 77 and three

weeks instead of 77 and one week. One commentary that was published

along with one of these results said this is the equivalent of

rearranging the [deck] chairs on the Titanic.

 

So you think right off the bat something went wrong. Clearly the

differences between these countries has to be environmental factors?

 

Yes. The idea was, when you follow immigrants from one country to

another, they tend to adopt the heart disease rates and cancer rates

of the country they've moved to, so that suggests that it's not

genetic, it's environmental. And then the question is: What is the

environmental factor?

 

In the '50s, '60s, and '70s, there were a school of British

researchers who said it's sugar, flour, white rice, what we now call

" easily digestible carbohydrates " or " high glycemic-index

carbohydrates. " The diet doctors pushing low-carbohydrate diets, like

Atkins and Taller and people like this, were sort of disciples of

these British researchers. They read some of their writing, ad the

idea was, primitive peoples, when they adopt Western diets, [they]

adopt Western diseases as well: diabetes, heart disease, obesity, the

foremost ones; some cancers -- colon cancer and breast cancer.

 

These British researchers pushed this theory and it kind of got run

over by the dietary fad, cholesterol, heart disease dogma. [Other]

researchers said: Well, if sugar and refined carbohydrates don't raise

cholesterol, then they can't cause heart disease. Or if we can't prove

beyond a shadow of a doubt that every country that has a high sugar

consumption has high heart disease, then that means the theory's not

true.

 

There were two different standards at work. In the heart disease

dogma, every piece of positive evidence supported the hypotheses and

moved it forward, and every piece of negative evidence, contradictory

evidence, was ignored. In the refined carbohydrates theory, every

piece of negative evidence was proof that the theory was wrong, and

every piece of positive evidence was ignored. So you had two entirely

different standards. One of them moves forward to become the theory

we're living by today, this idea that if we cut back on fat, we'll be

healthier. And the other sort of gets squelched.

 

You start to see the quality of this science, the foundation, is not

what you thought?

 

Well, the first thing I did, I wrote an article for the journal

Science, where I just looked at the question of fat and heart disease.

And it was fairly clear from that, that if saturated fat has any

effect on our heart disease risk, it's small. Having done that, and

not being enraptured by this idea that saturated fat is evil, I then

actually just pitched a story to The New York Times Magazine, saying,

" I want to find out what started this obesity epidemic. "

 

The obesity epidemic starts between 1976, say, and 1986. We're fairly

confident about that because there're these series of National Health

Examination surveys, and we know that in the third NHANES survey,

obesity rates are still 14 percent.

 

Up until about 1980.

 

Yeah. Basically, up until about 1980, the obesity rates in this

country are 12 to 14 percent. And then somewhere in that period

between the late '70s and late '80s, they shoot up to 22-25 percent.

That's known as the obesity epidemic, and the idea is: What explains

it?

 

From my fat research, I already knew that there were two major changes

in the country during that period. One was, high-fructose corn syrup

came in as sort of the primary caloric sweetener in America, which was

my personal bias. I thought that it was high-fructose corn syrup

because I'm allergic to high fructose corn syrup. …

 

The other theory was that we started pushing the low-fat diets during

this period. Starting in 1977, the government started telling all

Americans to eat less fat, and starting in the mid-'80s, we started

producing these low-fat products that in effect replaced the fat in

the yogurt or the cookies or the whatever with carbohydrates. We went

from being a country that ate about 40 percent of their calories in

fat and 45 percent carbohydrates, to 34 percent fat and that much more

carbohydrates. Conceivably, this belief that set in, that

carbohydrates could be eaten to excess and wouldn't cause weight gain,

that they were both heart healthy and the ideal diet, might have had

some effect on weight.

 

I just went off to try and find out what the answer was. I didn't know

when I went in, and the more research I did, the more it became clear

that this argument, this hypothesis, the alternative hypotheses that

carbohydrates cause weight gain, had validity. Didn't mean it was

true. Just meant that it had validity. It could be true, and if it

could be true, then the way you would check is to put people on

low-carbohydrate diets. You go and look at the low-carbohydrate diet

idea, and lo and behold, there's Robert Atkins, who's been pushing

low-carbohydrate diets for 30 years, and people swear by them. I had

my former experience where I knew that at least for me, I knew it was

very easy to lose weight on this diet.

 

I found out while I was doing my reporting that there had been five

studies recently done, clinically controlled trials comparing

high-fat, high-protein diets like Atkins to low-fat, low-calorie diets

of the kind the American Heart Association was recommending. And in

each case, the people on the Atkins diet had twice the weight loss,

and their cholesterol profiles, if anything, got better than the

people on the American Heart Association diet. So I felt confident

saying: Here's an alternative hypotheses that has validity. Here is

one set of tests from the hypotheses, that seem to confirm it. Doesn't

mean it's true, but it seems to confirm it, and what now needs to be

done is more studies.

 

So your article comes out. … What was the reaction?

 

Some people said it was the best article they ever read, went on the

diet. I got crucified in a variety of publications. A Washington Post

reporter went after me, who had been advocating low-fat diets since

the early 1980's. The Center for Science in the Public Interest went

after me for having the nerve to suggest that low-fat diets might not

be healthy. They'd been probably the primary force in the 1970s

pushing low-fat diets, and through the 1980s. It was fascinating. They

go after the messenger as much as the message. ...

 

[Talk about the difference between diet and other topics you have

covered.] Is there more ideology?

 

Certainly diet became a religion. The whole low-fat idea, as much as

anything, came out of the counterculture and Berkeley and San

Francisco in the '60s, this idea that eating fatty meat, in effect, is

the dietary equivalent of conspicuous consumption. There were famines

going on around the world, people were starving, and here in America

we were eating eggs and bacon for breakfast and huge steaks for

dinner. This was just unacceptable politically, sociologically,

ideologically. It merged with this idea that fat might cause heart

disease, and then blossomed in the '70s.

 

Many of the health reporters who cover this, many of the researchers

who report on it, are vegetarians or close to vegetarians. So it

becomes much more than just a subject -- I mean, people are more

polarized in this than they are in politics. I've had friends who have

accused me of having a brain transplant, because suddenly I turned

around and said maybe low-fat diets don't work, and may

low-carbohydrate diets are the answer. It's as though the data becomes

irrelevant. The evidence becomes irrelevant. Everyone knows what the

answer is, and it's a little frustrating even from my point of view,

because no matter how much research you do, you're going after a

monolithic dogma, in effect. And dogmas protect themselves.

 

That's what I found out when I wrote my Times piece. Everybody

involved says, " We're right. We've invested our whole lives in this.

We believe it. " Everyone believes it, and it's hard, once it's

established, to even criticize it or be skeptical without being pegged

as somebody who's self-interested or somebody who doesn't care that

Americans are out there dying of heart disease.

 

Nutritionists do admit anecdotally that Atkins works. How do they

explain it away?

 

The first Atkins-like diets were explained away because the people who

advocated them suggested they had a metabolic advantage over low-fat

diets. Say you have two diets that are 1,200 calories, one's low fat,

one's low carbohydrate. These people said the low-carbohydrate people

will lose more weight on the same amount of calories. Researchers came

along and they did studies and they said, " No, if we give both groups

1,200 calories, they're going to lose the same amount of weight. " So

that allowed them to say the [low-carbohydrate] diets are no different

than any other diets.

 

Then the diets kept coming up. They kept being popular. And the next

question was: Well, the people on the low-carbohydrate diets don't eat

as much calories, so even though you tell one group of people, " Eat

less fat and east less calories, " [on] a calorie-restricted diet, and

[for] the Atkins-like diet, you say, " Eat as much fat as you want, eat

no carbohydrates, eat as much food as you want. So you can go out and

have 10 porterhouse steaks a day, but as long as you don't eat

carbohydrates, you're going to lose weight. "

 

First the critics said this is thermodynamically impossible. Who

knows? I have no idea. If you eat 10 porterhouse steaks a day, maybe

you'll lose weight, maybe you won't. That's another long story.

 

So [low-carb advocates] said, " Okay, if people are losing weight on

this diet, we're telling them to eat as much as they want but they're

eating less. So why are they eating less? Why is it so easy for them

to eat less? " And the answer was: Well, they're either getting

nauseous, because this state of ketosis which is caused by these diets

can sometimes create nausea in the beginning, or you just can't

replace the calories. If you give up the carbs in the diet, you can't

eat enough fat and protein to make up for it -- which is kind of

ironic because since the early 1980s, we've been told that what makes

us fat is not the bread but the pat of butter we put on top of it, not

the baked potato but the sour cream that [we] put on top of it. It

just seems that they want it both ways. On one hand they say, if we

just add one pat of butter and sour cream to a baked potato, on our

white bread, we're going to get fat, and it's the butter and the sour

cream that do [it]; but if we only eat the sour cream and we only eat

the butter, we can't replace the bread and the baked potato with

enough meat or fish or cheese or whatever, to replace those calories.

....

 

The other response to the Atkins diet has been to say it was

unhealthy.

 

Yeah, there're two factors. The Atkins diet, because it's very low in

carbohydrates, it can be ketogenic. That's why your body, in effect,

stops running on glucose, on blood sugar, and starts running on fat,

and the fat's broken down into these ketone bodies. Ketosis is a mild

version of diabetic ketoacidosis, which is the state that occurs in

uncontrolled diabetes, and it's fatal.

 

This whole medical society grew up basically thinking ketosis is bad,

ketoacidosis is bad, and therefore ketosis in these diets is bad and

you should do anything you can to avoid these ketogenic diets. In

fact, many of the compromise diets from the 1930s through the 1990s

were diets that cut back carbohydrates to just the level above which

you won't have ketosis.

 

So on one level, ketosis is bad. That was always the message, and the

other level was, these diets are high in fat, and if they're high in

fat, they're going to cause heart disease. One study was done by this

fellow John La Rosa, who went on to be a big administrator in the

American Heart Association. He did a study in 1981 where he said he

put these people on a Atkins diet and their cholesterol levels

skyrocketed. Their weight plummeted, and if you actually look at the

study, it's almost impossible [that] what he says happened. It's

really fascinating that you take somebody from the American Heart

Association, you have him do a study on the Atkins diet in 1981, and

the cholesterol levels skyrocket, even though the people lose like

20-30 pounds. What he said happened should not happen, even if the

diet was atherogenic, as they say.

 

Then 20 years later, you have unbiased people do the same experiment.

Lo and behold, cholesterol doesn't go up at all. [However], once [the

American Heart Association] showed that cholesterol went up, that was

the end of the Atkins diet. Cholesterol caused heart disease. You go

on this diet, it may reduce your weight, but you're going to die of a

heart attack.

 

One of the things I had always tried to understand, the orthodox

wisdom is [to] cut back. Just eat less, and yet people eat less and

they don't lose weight. I've eaten less and I've not lost weight. I

mean, it doesn't seem to work, and I kept saying to myself: Why can

you tell people over and over again [to] eat less, and yet they don't

lose any weight? One possibility is that every time you tell them to

eat less, you tell them to eat less fat as well. That's what we did in

the '80s and '90s. We even stayed away from avocados and peanut

butter, which we now know have good fats in them. ...

 

And now the consensus is that the Atkins diet is not necessarily

dangerous but it's a trick.

 

Yeah, that's the compromise position: " Okay, it doesn't raise

cholesterol. We were wrong about that. " Other people said, " well,

there're probably other reasons saturated fat causes heart disease. "

It's fascinating. There was this train of logic that said saturated

fat raises LDL cholesterol and that's a risk of heart disease. Then if

they come up with a diet that says saturated fat doesn't raise LDL

cholesterol, then they turn around and they say: " Well, saturated fat

must cause heart disease in other ways. " So saturated fat, by virtue

of being saturated fat, is now unhealthy. There's nothing you can do

to change that. Even if you have a diet high in saturated fat that

doesn't raise cholesterol, it's still a risk factor for heart disease.

The logic is circular and sophistic. …

 

The thing they never pay attention to -- and I've interviewed probably

300 or 400 researchers in the obesity/heart disease field in the past

four to five years, and in obesity in particular -- they do not

consider hunger a physiological phenomenon. They will talk about

hunger hormones, hunger genes ... But hunger to them has always been

something that's purely psychological on some level, so they could put

people on a diet.

 

Now, here's the thing. If you just reduce the amount of calories,

you'll lose weight, even though there's not a single study that's ever

shown that. But this [is] what they know for sure, so we're going to

put people on a diet, we're going to tell them to eat less calories,

and if they don't lose weight, that's because they didn't eat less

calories. If they didn't eat less calories, that's because they don't

have any willpower, and willpower's some psychological concept that

you don't have but I do. I'm thin because I have willpower. And that's

what it comes down to. …

 

When you look at the history of these Atkins-like diets, like the

protein-sparing modified fast -- which is a sort of fancy name for an

Atkins-like diet with a little more protein and a little less fat --

when you look at the history of these studies, even the ones that said

they didn't have a metabolic advantage over low-fat diet, they all

said the patients, the subjects didn't seem to be hungry. Study after

study from the '40s onward. We put them on the diet, if they eat less

calories, they do it because they just don't seem to be hungry. That's

a physiological phenomena, and you have to be able to explain it. ...

 

So high-carb diets, even with less energy density, make you hungrier

and therefore make you fatter.

 

That would be the theory. Exactly. You're hungrier. Insulin actually

used to be known as a hunger hormone up until about the '60s; the idea

being, diabetics are hungry to begin with because they don't have the

insulin to push the blood sugar and the fat into the cells, so their

cells don't see it. There used to be a treatment for anorexics. You

would just inject them with insulin and they get hungry and eat. The

question was: Does this cause some kind of hypoglycemia, very low

blood sugar? Is that how it works? Or does it work in some other way?

It was always assumed that it works by just causing very low blood

sugar, which in effect causes a state called hypoglycemia, and you get

nauseous and dizzy and tired, and you have to eat.

 

But [now] everyone agrees that insulin is the hormone that controls

the deposition of sugar and carbohydrates and fat in your body. They

agree that if insulin levels are high, you'll preferentially store

calories as fat; and that as long as insulin levels stay high, you

won't be able to get to that fat to use it for fuel. They agree that

carbohydrates will raise insulin levels more than -- fat doesn't have

an effect on insulin, although if you force-feed enough calories, you

can [raise] it. All of that is given.

 

What they don't agree is that somehow the carbohydrates, the actual

macronutrient content of the diet, will do this. [scientists] will say

a calorie is a calorie is a calorie. They'll admit that a calorie of

carbohydrates has an entirely different effect on your hormonal system

than a calorie of fats. They'll admit that your hormones can control

your weight; that insulin and estrogen have effects on weight, hunger,

and body weight regulation. But they will never go from the step where

they say: Hey, maybe the amount of carbohydrates and the kind of

carbohydrates in the diet will have an effect -- through their effect

on insulin, through insulin's effect on the deposition of calories,

through that effect on hunger -- [on] being a functional diet.

 

To me, it's almost mystifying, because I've interviewed people who

have done research on each step of the way. And then I say, " This

should be the null hypotheses. You should assume carbohydrates cause

weight gain until proven otherwise, not the other way around. Why

don't you believe that? " And they'll say, " Well, because my rats get

fat on fat. " And it's true. Rats will get fat on dietary fat, fatter

than they will on carbohydrates. So then the question becomes: Are

rats a good animal model for human obesity?

 

So this theory would explain a big part of the rise of obesity on the

high-carb diets?

 

This theory would explain a big part of the rise of obesity on the

high-carbohydrate diet. Yes. Basically it says: The things that are

making us fat -- sugars, high-fructose corn syrup, these kinds of

easily digestible sweets, flour -- some people may get fat even if

they eat vegetables. I really don't know because they've never done

the research. Because they've been so convinced that somehow the type

of calorie is irrelevant, I'm not sure this is still an open question.

But the theory would explain why we started putting on weight just

when we started thinking " if we would just reduce the amount of fat in

the diet, that'll make the difference. "

 

It's not just the calories. That's the point. It's the effect of the

calories on the hormones, and the effect of the hormones on how your

body decides to use the calories you're eating -- is it going to burn

them as fuel or store them as fat -- and that effect on hunger.

 

But clearly the quantity of calories has to be going up. You're saying

the mechanism for that is that the carbs make us hungrier?

 

The quantity of calories appears to be going up. Whether we would get

fat anyway -- we've all had this experience where our weight

fluctuates, apparently independent of how much we seem to be eating.

If you chronically change your insulin levels, you will change your

weight by doing it. So the question is: Can you do that by increasing

calories, or do you do that simply by increasing carbohydrates and

keeping the calories constant? Good research in the '80s by

established researchers showed you can do that just by changing the

amount of carbohydrates. ...

 

Does your story have big holes in it too? Every time you try and

reduce things to single macronutrients, you run into--

 

No, actually, you look back to one of the things that prompted the

whole dietary fat and heart disease theory was the reduction in heart

disease rates in occupied Europe during World War II -- and diabetes

rates and cavities, I might add -- they plummeted. People said they're

eating less cholesterol. Then that was knocked down. Then they said

they were eating less fat, and that was the theory.

 

Out of these studies that came out of occupied Europe, that was what

generated one of the major legs of the theory that fat -- it's a

tricky question because you can also argue that doctors in occupied

cities in Europe and Scandinavia might not be making the effort to

diagnose heart disease and diabetes as they were during the war, or

before the war or after. The evidence that something dramatically

changed the incidence of disease during the war years is pretty

compelling. It could have just been less calories. We're now fairly

confident that if you cut back on calories, you'll cut back on disease

rates, and not just heart disease but cancer. But the question is:

Then what makes you cut back on calories? And now you're back to, you

know, Ancel Keys tried to get his conscientious objectors to cut back

on calories. So now you're back to what causes hunger. And it takes

back into this same hypotheses.

 

Most researchers now would say that calories are probably the most

important factor, calories and weight, so you're still left with: What

is it that makes you eat more calories?

 

What would be your prescription for curbing the obesity epidemic?

 

There's compelling evidence that low-carbohydrate diets work. Clinical

trials suggest they work, [as does] anecdotal evidence for 150 years.

People, when they wanted to lose weight, gave up sugar, gave up starch

and we all grew up believing this, even into the '70s. Jane Brody, the

New York Times health reporter, writes a bestselling book in 1985

where she tells everyone to go out and eat starches to their hearts'

content, but first she says we all grew up believing that what causes

obesity is bread, rice, pasta, potatoes, sugar.

 

It's fascinating. For 150 years since Jean Anthelme Brillat-Savarin in

1825 writes The Physiology of Taste and says, " I know what cause

obesity. Just talk to fat people. They eat too much starches and

sugars. " He says this. " I have 500 conversations over the year with

stout people, and each one, they're telling me, 'I love the potatoes.

I love the rice. I love the bread.' " Since then, it's sort of been

institutionalized that carbohydrates -- starches and sugars -- make

you fat.

 

The '70s come around. We decide that fat gives you heart disease. We

have to eat low-fat diets, low-fat diets heavy in starches and sugars,

and we start getting fatter. ...

 

You're not talking about a diet with no carbs, just a reduced amount?

 

The underlying philosophy is this kind of Paleolithic diet theory.

It's what we ate during the 2 million years that we were

hunter-gatherers on this planet. The fact that we were

hunter-gatherers for 2 million years suggests it was an

extraordinarily successful evolutionary adaptation. The question is:

What did we eat during these 2 million [years] when we left the

jungle, the trees, went down into savanna and started surviving on

whatever we could hunt or gather? That's the philosophy. The answer

is, probably considerable meat, very low glycemic index,

hard-to-digest roots and starches, and fruits and berries that look

nothing at all like the beautiful Fuji applies you can buy at your

local market now. Some carbohydrates, but whatever it was, it wasn't

refined. It wasn't sugar. It wasn't flour. It wasn't easy to digest.

That's my going theory. If this theory's right, the diet we evolved to

eat is probably the correct diet.

 

Just as [with the] low-fat fad, when manufacturers took fat out and

put carbs in, and people ate a lot of low-fat ice cream because they

thought it was not fattening, and they got fat, might not the same

thing happen if you produce low-carb products?

 

It's conceivable. The idea that it's what we evolved to eat, we never

evolved to eat refined protein either, which is basically what they're

giving us. I have no idea what those foods will do in the long run. I

mean, I've actually tried quite a few myself, and they don't seem to

affect weight in any way. They do seem to keep insulin levels down, if

that's what's actually happening. ...

 

Unlike Walter Willett, who says some fats are good but others are bad,

you'd say a quarter house steak would be a perfectly decent meal?

 

Let's put it this way. When you look at the historical record and the

literature, you find plenty of reasons to blame the refined

carbohydrates on the chronic diseases that affect us, and it's hard to

come to a point where you can finger saturated fat as actually being

meaningful. There's this interesting theory, originally pushed by a

fellow named Crawford, who was a researcher in Kenya in the '60s. It's

this idea that the grazing animals eat a much wider variety of fats

and carbohydrates. They have much great sort of tapestry of fats in

their body, and they have much more unsaturated fats than saturated

fats, and therefore that constitutes a healthy meal. That's a shift in

the spectrum of fats we're eating, not the introduction of an entirely

new type of food, like refined carbohydrates.

 

The question is: Can that shift in the spectrum from more unsaturated

fats to more saturated fats really be that important, after you've

removed this dramatic shift of no refined carbohydrates to refined

carbohydrates? I don't know, and Walter doesn't know either. He's just

telling you that he believes it's the case. ...

 

The other theory has to do with activity. We're an increasingly

sedentary society.

 

One of the problems with that theory is that the highest obesity rates

in this country are in the poorest members of the population. [Those

scientists] have to explain, for instance, why it is that those

individuals who are most likely to do manual labor are the ones who

are most likely to be obese. Hispanics, for instance, come to America,

they get high obesity levels here, and they're not coming here and

taking white-collar jobs. You have to be able to explain that before

you can say it's obesity.

 

You have to be able to explain why it is they've never been able to

show that if you exercise more, you'll actually lose weight. When you

read the research articles from the '70s and '80s and '90s, they're

fascinating. They'll always start with a introduction that says

exercise and physical activity is crucial to weight loss and weight

maintenance. Then they'll move into the main part of the paper, where

they'll go through study after study after study, where they

acknowledge that these studies fail to show that you could actually

lose significant weight by exercising or being more active. Then

they'll get to the conclusion, and they'll give you a half a dozen

techniques by which you can then make exercise part of an important

weight loss or weight maintenance program. It's surreal reading these

things. The book ended [with] the advice that you have to exercise,

but the actual studies show that doesn't do any good.

 

They say the people who control their weight the best tend to be more

wealthy, better educated. What are they doing right?

 

First of all, they say that the same people also experience an obesity

epidemic. Their absolute levels of obesity are lower than the lower

classes, but the amount that obesity increased was the same. Among

poor, rich, it didn't matter. They all went up like 7 percent during

this 10-year period of time.

 

Second thing is, carbohydrates are the cheapest calories. So the

poorer you are, the greater the amount of carbohydrates in the diet.

You go back and you read the obesity textbooks and the obesity

monographs in the '60s and '70s, and people have to explain why

there's so much obesity among poor people, and they invariably say,

" Well, that's because they eat so much fattening starches. " You had

this concept once again of fattening starches. ...

 

What do you hope to achieve, writing your book? You're making a case

that there's a lot of bad science, food ideology. Are the vested

interests too powerful to change?

 

It's interesting. In my wildest fantasies, people are sort of

liberated from this belief that they have to reduce the fat in their

diet, and they try it. If they're overweight and they want to lose

weight, they try going back to the old-fashioned way of giving up

sugars and starches and seeing what happens. In writing the book, I

want to explain what to me is a fascinating episode in science sort of

gone awry, and in the same time write about some fascinating science

that's simply been ignored, some beautiful, elegant studies that

people have paid no attention to, and maybe show some people not just

how body weight regulation works in the human body, why we gain

weight, why we lose it, and what to do, but also explain how science

works and how it doesn't work, and when it is successful and when it

fails, and what's good science and what's bad science. That's what

I've been writing about in my whole career.