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The amount of disease that could be prevented
through modifying one's diet?
The potential impact of healthy diet, when you combine it with
not smoking and regular physical activity, is enormous. For example,
our studies have shown that we could prevent about 82 percent of
heart attacks, about 70 percent of strokes, over 90 percent of type
2 diabetes, and over 70 percent of colon cancer, with the right
dietary choices as part of a health lifestyle. The best drugs can
reduce heart attacks by about 20 or 30 percent, yet we put almost
all of our resources into promoting drugs rather than healthy
lifestyle and nutrition.
Do you think the government agrees with you
about what's at stake?
I think the government has under-funded research in diet and
nutrition. In some ways we blame the abstract government for it, but
in some sense it's also the scientific community that's partly to
blame for it, because we often tend to fund the novel, exciting
science, the new gene discoveries, the new mechanisms of drugs, for
example. Often diet and nutrition and lifestyle are perceived to be
sort of passŽ or too simple, and yet they are very important
topics. There is interesting science behind it, but because it's not
regarded as so novel and new, it's often neglected in scientific
funding.
What caused the shift from how much you ate
to what you ate?
If we look back at the beginning of the 20th century, over 100
years ago, the main problems were under-nutrition, even in the
United States. During the first few decades of the last century, we
discovered vitamins and minerals and the necessity for having those,
and it was clear that many people were not getting enough of those
critical nutrients. But we solved most of those problems, in fact,
and about the middle part of the last century we started to
appreciate that there was a huge epidemic of heart attacks, coronary
heart disease and strokes emerging. …
Tell us about Ancel Keys, looking at
different countries.
One of the ways that we appreciated that diet and lifestyle might
really be important was the work of Ancel Keys, who looked at 14
different populations across Europe and Asia. What he realized was
that there were some groups -- for example those living in Crete and
some villages in Japan -- where heart disease rates were extremely
low, only about one-tenth of those in the United States. And yet we
also knew, when people moved from those environments, those
lifestyles, and lived in the United States, they developed heart
disease rates that were very high, just like everybody else in the
United States. So that was powerful information telling us that
there was something about the diet and lifestyle, way of life, that
was extremely important in determining our risk of heart attacks.
Where did the idea of saturated fat come
from?
The idea that saturated fat was a major underlying factor for
heart disease did come about largely from the work of Ancel Keys,
where he looked at various countries around the world and looked at
their heart disease rates, and found that they were strongly
correlated with saturated fat in the diet. However, even Keys
recognized that it was difficult to point the finger totally at
saturated fat, because there were many other aspects of diet and
lifestyle that were different among these various population. ...
It was suggested we would do better with more
vegetable oils?
Building on the work of Ancel Keys that showed that countries
with high saturated fat had high heart disease rates, there were a
number of detailed studies looking at, if we fed different types of
fat, how would they affect our blood cholesterol? And it was found
that saturated fats increased our blood cholesterol, and
polyunsaturated fats from liquid vegetable oils reduce our serum
cholesterol. And so in the mid-1970s, the predominant dietary advice
was to replace saturated fat with polyunsaturated fat.
As it turns out, that advice was probably very good and had
additional benefits beyond just those that influence serum
cholesterol levels, in that [the] increase in polyunsaturated fat
was probably largely responsible for the major reduction in heart
disease rates we had during the '70s and early '80s in the United
States. In fact, the rates of heart disease death went down by about
50 percent during that time.
The movement to get people to switch the
types of fat: isn't this a heroic struggle that we should feel proud
of?
Actually, I think we should be very proud of the achievements
that were made during the 1970s, early 1980s, changing the type of
fat in diet. We really made some very major national changes, and it
did have some important benefits in reducing heart disease rates.
This low-fat dogma was incorporated into the
USDA food guide pyramid in 1992?
Well, there's a little bit of complexity. It's interesting. In
the '70s and early '80s, while heart disease rates were going bad,
we were not talking about low-fat diets. We were talking about
replacing saturated fat with a healthy fat, polyunsaturated fat. But
somewhere in the mid-1980s, we lost that message. It's perhaps
partly because some nutritionists felt it was too complicated to
talk about different types of fat, and developed the notion we
should just reduce all types of fat across the board. That was
really the beginning of the low-fat, high-carbohydrate crusade.
From the beginning, people said you should
limit total fat but the amount of saturated fat was less? There
wasn't always a distinction?
If we go back to the 1960s, 1970s, it was really not so much even
limiting total fat. It was really a replacement, and a strong belief
that polyunsaturated fat was good. In fact, it really turned out to
be that that was right.
[What are] examples of the types of fat?
What we were talking about when we meant replace saturated fat
with polyunsaturated fat was reducing foods like butter, lard, the
fat in red meat, with liquid vegetable oils and things made from
liquid vegetable oils.
How is the simplification -- eat less fat --
manifest in this food guide pyramid?
Well, the food guide pyramid that was developed in 1991 really is
based on the idea that all fat is bad. Therefore [if] fat is bad,
and you have to eat something, carbohydrate must be wonderful. So
the base of the pyramid is really emphasizing large amounts of
starch in the diet. We're told we can eat up to 11 servings a day,
and if that wasn't enough starch, the pyramid puts potatoes along
with the vegetables, so you can have up to 13 servings a day. That's
a huge amount of starch.
Where's fat?
Fat's up at the top of the pyramid, and where it says explicitly
"fats and oils, use sparingly." It doesn't make any
distinction about the type of fat, and it tells us to eat basically
as little as possible.
From a public health standpoint, how would
you characterize this pyramid?
Well, this pyramid is really not compatible with good scientific
evidence, and it was really out of date from the day it was printed
in 1991, because we knew, and we've known for 30 or 40 years that
the type of fat is very important. That was totally neglected.
[What were the] unintended consequences? The
food industry started using vegetable oils, but baking was difficult
so they made a technical modification.
In some ways, we do have to credit the food industry with being
responsive to what nutritionists were saying. They did believe or
accepted the evidence that vegetable fats, vegetable oils, would be
better than animal fats, and that really led to the development and
promotion of the margarine industry and Crisco, baking fats that
were made from vegetable oils. But they were made by a process
called partial hydrogenation, which converts a liquid oil, say like
soybean oil or corn oil, to something like margarine or vegetable
shortening. As it turns out that was a very disastrous mistake,
because in the process of partial hydrogenation, a totally new type
of fat is formed called trans fat. The evidence has now become very
clear that trans fat is far worse than saturated fat.
So when people were told to switch from
butter to margarine?
Unfortunately, as a physician back in the 1980s, I was telling
people that they should replace butter with margarine because it was
cholesterol free, and professional organizations like the American
Heart Association were telling us as physicians that we should be
promoting this. In reality, there was never any evidence that these
margarines, that were high in trans fat, were any better than
butter, and as it turned out, they were actually far worse than
butter.
People read on the label "cholesterol
free."
Right. This is a good example where just focusing too much on one
particular piece of the diet, one particular substance or nutrient,
can really mislead us. It is true that these vegetable shortenings
and margarines were cholesterol-free, and that was pushed. ... Even
though these products were cholesterol-free, the trans fats in them
raised our blood cholesterol much more than actual cholesterol in
the margarines would have done.
"All fat is bad" led to many
low-fat products, some of which had beneficial value. Talk about one
example.
This campaign to reduce fat in the diet has had some pretty
disastrous consequences. ... One of the most unfortunate unintended
consequences of the fat-free crusade was the idea that if it wasn't
fat, it wouldn't make you fat. I even had colleagues who were
telling the public that you can't get fat eating carbohydrates.
Actually, farmers have known for thousands of years that you can
make animals fat by feeding them grains, as long as you don't let
them run around too much, and it turns out that applies to humans.
We can very easily get fat from eating too many carbohydrates, and
the public was really directed to only focus on fat calories, when
we really have to keep an eye on calories no matter where they're
coming from.
With more fat-free products than ever,
Americans got fatter.
Right. The reality is that during this campaign for fat-free and
reduced-fat products, actual fat consumption did go down, but
Americans got much fatter during this period of time. Now of course
lots of things were going on at the same period in time, but I think
it's highly likely this focus only on fat calories to the neglect of
carbohydrate calories has contributed to this epidemic of obesity.
Is it fair to blame the food pyramid when
people don't follow it anyway?
The food guide pyramid has actually had a substantial impact on
the diets of Americans. If we look back compared to 20 years ago,
the percentage of calories from fat in the American diet is quite a
bit lower compared to earlier days. Second, there're some important
indirect impacts of the food guide pyramid, in that many tens of
billions of dollars of federal food policies have to be compliant
with the food guide pyramid. So many programs -- for example, what's
fed to young children, to pregnant mothers, to low-income families
-- have to be consistent with low-fat diets. So the impact really
has been, overall, substantial.
Behind the food pyramid were a collection of
constituencies. Were people receptive when you raised these
criticisms in the '90s?
There was not much receptivity in the 1990s, when we raised these
criticisms of the food guide pyramid. It was almost an accepted
religious belief that fat was bad and carbohydrates were good. Then
there were lots of economic interests behind the food pyramid as
well. Clearly the dairy industry is extremely well represented in
the food pyramid. The beef industry is there, and it's very
convenient that beef is combined along with fish and poultry and
nuts and legumes. So each one of those industries can say: It's
healthy to have three servings a day of our product.
What makes it so difficult to study the
relation between diet and health?
The relation between diet and health is unusually complicated to
study, and that's probably why we don't have all the final answers
even yet. In a trial of a drug, for example, you can randomly assign
people, one group to a placebo and another [group] to the new drug,
and see what happens to them. But obviously you can't do that with
nutrients or a whole diet very easily.
Second, we have to follow people for many years to learn all the
consequences of diet, and perhaps even almost a lifetime, because
some of the effects of diet may be operating during childhood and
not be manifested until adult life. So there's no one simple kind of
study that will give us all the truth about how diet influences our
health, and we need to combine the results of many different studies
to have the best and most complete picture.
One [kind] of study, for example, involves feeding small groups
of people very controlled diets for short periods of time, and
seeing what happens, for example, to their blood cholesterol levels.
But blood cholesterol levels are only part of the picture, so we are
also conducting very large studies where we enroll tens of thousands
of people and follow them for many years, all the way along, finding
out what they're eating, and then what happens to them in terms of
their risk of heart attacks, cancers, and other conditions. And of
course in those studies we need to control for many factors, like
whether they smoke, how much exercise they have, their family
history of various diseases. It's really only when we put those
kinds of studies together with the more detailed metabolic,
biochemical studies that we can have the best information about the
effects of diet.
So you find out what they eat, rule out the
bad things they do, and look for associations?
Right. What we do is find out what people eat through very
detailed, structured questionnaires, observe what happens to them in
terms of disease rates -- heart attacks and cancers, for example --
and then put these together, controlling for other aspects of
lifestyle like diet and activity.
What did you notice that seemed to clash with
the low-fat dogma?
When we began our studies back in the late 1970s, we expected
that we would find a relationship between, say, fat intake and
breast cancer, because that was almost an accepted relationship. But
as the data started coming in over the years, we just did not find
any higher risk of breast cancer among women who consume more fat in
the diet. And the same was true for colon cancer and for heart
attacks and risk of type 2 diabetes. In fact, the percentage of
calories from fat in a diet has not been related to any important
health outcome.
Amount of fat has no relationship to coronary
heart disease?
The amount of fat had no relationship to risk of coronary heart
disease, but the type of fat was extremely important.
So the advice we were getting was not just
misleading but dangerous?
Right. The evidence that we accrued really suggested not only
that the type of advice that people were getting was not useful, but
it actually could be dangerous, because some people were eliminating
the very healthy types of fat that actually reduce heart disease
rates.
Certain fatty acids can dramatically reduce
the incidence of cardiac arrhythmia?
One of the important findings, not just from our studies but
several trials conducted by other people in Europe and also some
careful animal studies, have very clearly indicated that some types
of fatty acids in the diet, in particular the omega-3 fatty acids,
can actually reduce the heart arrhythmias that really cause people
to drop dead in the street. We call that sudden death. And that's
very important because some people were eliminating those critically
important fatty acids from their diet because they were told that
all fat is bad. ...
Traditionally people think of carbohydrates
as made up of simple sugars and complex starches. What's wrong about
that?
Right. The thinking in nutrition about carbohydrates really had
broken them down into two classes: sugars and so-called complex
carbohydrates, which are mostly starches. ... The idea has been
pushed that all forms of so-called complex carbohydrates are really
the poster child of nutrients, and we should be eating them in large
amounts. That's what the pyramid tells us to do. But in fact, these
kinds of starches -- white bread, white rice, potatoes -- are
starches that are very rapidly converted to glucose, really pure
sugar, and almost instantly absorbed into the bloodstream. And these
are the kinds of carbohydrates that we really should be minimizing
in our diets.
A sugar rush from a potato?
Actually, careful studies have shown, demonstrated that you get a
bigger rise in blood sugar after eating potatoes, a baked potato,
say, than you do from eating pure table sugar.
Really!
Really.
That seems pretty extreme. Why is that?
... There are several problems with these rapid rises in blood
glucose after you ingest large amounts of a rapidly digested form of
carbohydrate. First of all, when the blood sugar goes skyrocketing
up, the body wants to bring it back down. So our pancreas pumps out
a big blast of insulin, and as a result, the blood sugar comes
crashing down rapidly. In fact, in many people, after three and four
hours, it overshoots and actually become a little hypoglycemic, and
that rapid crashing down of blood glucose and insulin stimulates
hunger. That would be no problem, except that it's often all too
easy to go in the refrigerator or find a snack, and if we do that
frequently throughout the day, that can add up to too many calories
over weeks and months and years, and contribute to obesity.
Second, these high rises in blood glucose and insulin have a bad
metabolic effect on the blood cholesterol fractions. Specifically
the HDL, the good cholesterol, is driven down, and triglycerides,
another type of fat in the blood that leads to heart attacks, goes
up.
Third, after many years of demand for high amounts of insulin,
the pancreas tends to give out. And at that point in time, we've got
type 2 diabetes.
[What is the role of insulin?]
The role of insulin is to transport glucose from the blood into
the cells, like into muscle or into fat cells.
What can go wrong with this system?
Well, the problem really comes about when we develop insulin
resistance. And that means that the cells, like the muscle cells,
become more resistant to the action of insulin transporting the
glucose inside the cell. And we can become insulin-resistant in
several different ways. There's some genetic component, and as it
turns our, for example, many Asians tend to have more insulin
resistance. Also if we have overweight or low levels of physical
activity, we'll be more insulin resistant.
Many people argue the virtues of Asian diets,
with a lot of white rice.
Right. The Asian diet as it's traditionally been used raises some
very interesting issues in nutrition, in fact, some of the most
important findings during the last several years. What we've come to
realize is that if we have a higher degree of insulin resistance,
then we much less well tolerate a high-carbohydrate diet.
Interestingly, in traditional Asian societies, people were very
lean, very active, and therefore had low insulin resistance. They
could eat large amounts of rice, even white rice, in the diet and
have low heart attack rates and have low rates of type 2 diabetes.
But if you take that same person, and they [now] may be living in
Beijing and driving a car and watching a television, and they put on
a few pounds, they're going to have much more insulin resistance. So
if you take that same diet, high in carbohydrate and white rice,
they will have a much worse metabolic response and much higher rates
of type 2 diabetes.
If you're American and overweight, won't you
be put on a low-fat diet?
If you're overweight and living in the United States, and you go
to a hospital and see a dietician, almost for sure, you're going to
be put on a low-fat, high-carbohydrate diet.
What's your view of that?
The problem is that that's really the wrong diet for an
overweight person. Because the person is overweight, in general
they're going to have quite a bit more insulin resistance and much
less well able to tolerate low-fat, high-carbohydrate diet.
But fats have twice the amount of calories
per gram as carbohydrates. Doesn't it make sense to push the
low-calorie diet and therefore a diet low in fat?
There's been a very simplistic idea: Just because fats have more
calories per ounce than carbohydrates, we should be eliminating fats
or reducing fats to control our total caloric intake, in other
words, to help control our weight. What's really important though is
how satisfying a diet is, because we have very complex mechanisms
that control our total intake of calories, and it's become pretty
apparent that if we have a high-carbohydrate diet, particularly high
refined carbohydrate, it makes it much more difficult to control our
total caloric intake. That's probably because when we eat refined
carbohydrates, we get these swings in blood glucose and insulin that
lead to hunger between meals; whereas if we have a diet that's
somewhat higher in fat, we tend to be more satisfied over the long
run.
Is this what Dr. Atkins was saying 30 years
ago?
Dr. Atkins was saying as much as 30 years ago, that if we reduce
our carbohydrate intake to quite low levels, that will make it
easier to control our caloric intake and thus promote weight loss.
As it turns out, there is a strong element of truth in that. A
number of studies in the last year have looked in a very careful
way, comparing low-fat, high-carbohydrate diets with
reduced-carbohydrate diets, and in general people have done better
on the reduced-carbohydrate diets in terms of their weight.
Even though each ounce of fat has twice as
many calories, you eat fewer calories because they're more
satisfying?
Yeah. Well, first of all, this idea of how many calories per gram
of fat versus how many calories per gram of carbohydrate is a little
simplistic, because we almost never eat foods that are pure fat and
pure carbohydrate. They come in foods as mixes, and often with a lot
of fiber and a lot of water, and all of those things make a
difference as well. But what is really important in the long run is
how satisfying a food will be. And as it turns out, that many
high-fat foods -- sometimes like meat, but even think of a handful
of nuts -- are often very satisfying even though the physical amount
is not very great.
One of the interesting observations in the recent studies that
have compared high-fat diets with high-carbohydrate diets is that
there are a lot of differences between people; that it's not that
everybody loses a certain amount of weight on a reduced carbohydrate
diet. Some people lose a lot of weight. Other people hardly lose
any, so one of the things we have to come to understand better is
the reasons why there's such a difference in response to these
diets.
Talk about your
food pyramid.
We've tried to put together an alternative food guide pyramid
that would be based on the best available science. And of course it
is a little bit challenging to boil down a tremendous amount of
complex science to a simple graphic, and you really have to focus on
the things that are well established and important.
Right at the bottom, we put weight control and regular physical
activity, because overweight is the number one nutrition problem in
the United States. Almost everyone is going to need to exercise on a
regular basis if they want to control their weight over the long
run. And this also is a message that all forms of calories are
important.
On the next level, we put healthy forms of carbohydrate, meaning
whole-grain carbohydrates and healthy forms of fat, meaning from
vegetable oils, in the recognition that in most people's diet, most
calories are going to be coming from some source of carbohydrate and
fat. And what's really important is that those both be healthy
sources.
Some of those fats have come right from the
top of the other pyramid.
Right. What we've done is, we've brought some of those fats from
the top of the pyramid down to the base, because healthy fats are an
important part of a healthy diet.
The rest of the pyramid?
Our alternative pyramid, like the USDA pyramid, does emphasize
plenty of fruits and vegetables, but we've taken potatoes out of the
vegetable group. We've put legumes and nuts as a layer. If you want
to be a vegetarian, those are good protein sources. But moderate
amounts of poultry, fish, and nuts can also make a diet be a
non-vegetarian diet and still very healthy. And up at the top we've
put red meat and dairy products, dairy fat, because those are high
in saturated fat. ... At the top of the pyramid, we've put foods
like white bread, white rice, white pasta, and sweets as those that
should be used sparingly. And that was really the base of the USDA
pyramid.
Some nutritionists have criticized your
pyramid as "floating on a lake of olive oil."
The formal studies that had compared a more moderate fat intake
as we've suggested, with low-fat diets, have actually consistently
shown that people did as well or better controlling their weight on
a moderate-fat diet compared to a high-carbohydrate, low-fat diet.
Even good fats are more fattening than good
carbs. So they think you're contributing to the obesity epidemic, or
there's a risk of that. A tablespoon of olive oil is 14 grams of
fat.
There are all kinds of beliefs about the amount of fat in a diet,
tremendously strong opinions. What we really need is sound data, and
the studies that have been done show that people actually end up
controlling their weight at least as well, and usually better, on
moderate-fat diets compared to low-fat, high-carbohydrate diets.
Is it okay to get more than 30 percent of
your calories from fat?
The evidence is quite clear that it's perfectly fine to get more
than 30 percent of your calories from fat, and probably, in fact,
it's even better to be getting more than 30 percent of calories from
fat, if it's the healthy form of fat. ...
When you look at the causes of obesity, what
do you find?
The causes of obesity and the obesity epidemic in the United
States are extremely complex. In fact, obesity is sort of a tip of
the iceberg of tremendous social change that's been going on during
the last few decades. First of all, our activity patterns have
changed greatly. We have children and adults now watching on the
average, about four hours of television per day, and in study after
study, we've seen just the number of hours of television watching
being the strongest predictor of obesity. When I was young and came
home after school, we'd all go out and play, and our mothers would
have to drag us in for dinner. That doesn't happen very often
anymore. Often the mothers are not there. Kids are inside. The
television is used as baby sitters. We've also made it dangerous and
uninviting to walk to places, to walk to stores, to ride bikes in
urban areas, and that's removed an important amount of physical
activity from our lives as well.
So the physical activities pattern's changed, but the food
environment has also changed. We have food available fast and very
low-cost and very convenient, almost everywhere. The food industry
has invested many tens of billions of dollars in making their
products more attractive, more sweet, more salty, more sexy, more
seductive in every way that they can, and we're vulnerable to that
promotion, and we are eating more. So you put these two factors
together -- reduction in activity, heavy promotion of food -- and
you've got, not surprisingly, an epidemic of obesity.
Which we're exporting to the rest of the
world.
Unfortunately, what we've created is now being exported to the
rest of the world. And in almost every country, in Europe as well as
Africa, Latin America and Asia, rates of obesity are climbing
rapidly.
When you think about solutions, how can we
proceed?
The causes of obesity are very complex, and therefore any
response is going to have to be complicated and multi-faceted as
well. There is no single solution to this, but we have to do many
things to really solve this problem.
We've actually looked at this in a very detailed manner over the
past two years in the New England states, and identified eight
different areas that we have to really modify. For example, schools
have to change what's served, what's promoted in schools. The
healthcare providers -- physicians, nurses -- have to be providing
much better and effective advice to their patients about controlling
their weight. Work sites have to change. The whole food environment
and what we promote to children has to be somehow modified, and we
do have to protect children from these aggressive advertisements. We
have to change the physical environment to make it more conducive,
more attractive to bicycle to work, to destinations, not just drive
places. Many other things need to be done if we're going to solve
this problem, and it's time we really began.
The national obesity crisis, I mean, it's
really severe. And to hear you talk about it, it sounds like it's
hopeless to overcome it.
The crisis we're facing is severe, and it's getting worse.
Interestingly, the full consequences won't be seen for another 30 or
40 years, because it takes that long a time for the risk of diabetes
and the complication of diabetes to play out. But it's not hopeless,
and I think that's the good news. There are places, if we look
around the world, where people have been controlling their weight.
For example, in Japan and in Sweden, women have really not been
gaining weight as they've gone through midlife and gotten older, so
we do need to learn more about how they're doing it.
Also in the U.S. there are many people who are controlling their
weight successfully. Not everybody is going to be as successful,
even if they do the same diet and do the same amount of physical
activity, but many people are doing pretty well. And one piece of
evidence we have is that upper-income groups actually only have
about half the rate of obesity compared to lower-education groups.
So it's not hopeless, but we are going to have to devote many more
resources to doing this if, as a whole country, we're going to be
successful. ...
The advice for so long was: Buy something
that says "fat-free," or at least "low-fat" on
it. All these [salad] dressings, fat free. But not necessarily a
good idea?
In fact, a pretty bad idea, and that was really unfortunate that
the crusade against fat really led the food industry to produce all
these fat-free salad dressing products. The problem is that the fats
that were in the salad dressings were the healthy fats, the ones you
should be including in the diet. They were the unsaturated fats that
reduce our blood cholesterol levels, and we've also seen that they
reduce heart attack risk and type 2 diabetes, as well. So people
were giving up these healthy fats, and what we've seen is actually
an increase in risk of heart disease among people avoiding full-fat
salad dressings.
Of course one of the important roles of a full-fat salad dressing
is that it makes salads taste good, and we want people to be eating
those vegetables. So it's not that we're telling people to gulp down
bottles of salad dressing. We want them to use it on a salad and
enjoy it. ...
[At] the base of your pyramid, after
exercise: whole grains. Right?
Right. On the base of our pyramid, side-by-side, we put healthy
fats and whole grains. And that's because we do see positive
benefits in study after study, that there's lower risks of type 2
diabetes and heart disease, and probably better weight control as
well, with some whole grains in the product. And that's because
these carbohydrates are generally absorbed more slowly, they give
less of a spike in blood glucose, and they come with a whole package
of minerals, vitamins, and fiber that all have positive health
benefits. ...
Some of these diets, even South Beach, for
instance, say you're going to lose weight on this diet even if you
don't exercise. They're not advocating that I don't exercise, but
they're de-emphasizing it. You, however, are saying exercise is
really central. It's the base of your pyramid, right?
Right. Exercise is absolutely essential. Even though we might
think of exercising half an hour a day, and I ride my bike to work,
might be quite a bit compared to the average American, it's still
really pretty modest compared to what my grandfather did, who worked
in the fields for 10-12 hours a day. ...
Okay now, in the great tradition of American
reporting, I'll focus this all on myself again. I love nuts. My wife
harasses me. She's got great advice on most things, but she says,
"Don't eat nuts. Lay off nuts." You're my only hope.
Okay. Well, let me help out, because nuts are really one of the
neglected health foods on American grocery store shelves. They've
been given a bad rap by nutritionists because they are high in fat.
Most of the calories in nuts are from fat, but it's almost all
healthy fats. And what we've seen, interestingly, study after study
is that people who eat more nuts do not weigh more than people who
don't eat nuts. And it's probably because even a small amount can be
very satisfying, and we unconsciously replace other forms of
calories with the nuts when we consume them. Now of course, you can
overdo any good thing. So being a little bit sensible about that is
important.
What's also useful is to think of nuts not as a sort of added on
snack, but as a protein source. For example, I often have it with a
salad and that combination is a good meal. And there's ways to put
nuts into mixed dishes and casseroles and things like that. So with
a little creativity, they can really be an important part of a diet
and a very healthy part of a diet.
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