[Applause]

Surely, if there was some safe, simple, side-effect-free solution

to the obesity epidemic, we would know about it by now, right?

I'm not so sure.

It may take up to 17 years before research findings make it

into day-to-day clinical practice.

To take one example that was particularly

poignant for my family: heart disease.

You know, decades ago, Dr. Dean Ornish and colleagues published evidence

in one of the most prestigious medical journals in the world

that our leading cause of death could be reversed with diet

and lifestyle changes alone— yet, hardly anything changed.

Even now, hundreds of thousands of Americans continue to needlessly die

from what we learned decades ago was a reversible disease.

In fact, I had seen it with my own eyes.

My grandmother was cured of her end-stage heart disease

by one of Dean's predecessors, Nathan Pritikin, using similar methods.

So, if effectively the cure to our number-one killer of men and women

could get lost down some rabbit hole and ignored,

what else might there be in the medical literature

that could help my patients, but that just didn't have

a corporate budget driving its promotion?

Well, I made it my life's mission to find out.

That's why I became a doctor in the first place and why I started

my nonprofit site, NutritionFacts.org.

Everything on the website is free.

There are no ads, no corporate sponsorship.

It's strictly noncommercial, not selling anything.

I just put it up as a public service, as a labor of love,

as a tribute to my grandmother.

[Applause]

New videos and articles nearly every day

on the latest in evidence- based nutrition—what a concept.

Ok, so, what does the science show is the best way to lose weight?

If you want testimonials and before-and-after pictures,

you have come to the wrong place.

I'm not interested in anecdotes; I'm interested in the evidence.

When it comes to making decisions as life-and-death-important

as the health and well-being of yourself and your family,

there's really only one question:

What does the best available balance of evidence show right now?

The problem is that even just sticking to the peer-reviewed medical literature

is not enough as, “False and scientifically [misleading] unsupported beliefs

about obesity are pervasive” even in scientific journals.

The only way to get at the truth, then, is to dive deep

into the primary literature and read all

the original studies themselves.

But, who's got time for that?

There are more than half a million scientific papers

on obesity with a hundred new ones published every day.

Even researchers in the field might not be able to keep track

beyond their narrow domain.

But that's what we do at NutritionFacts.org.

We comb through tens of thousands of studies a year so you…

don't have to.

Very nice!

And indeed, we uncovered a treasure trove of buried data,

like today I'll cover simple spices, for example, proven in

randomized, double-blind, placebo- controlled trials to accelerate weight loss

for pennies a day, but with so little profit potential,

it's no wonder these studies never saw the light of day.

The only profiting I care about, though, is your health.

That's why 100% of all the proceeds I receive from all of my books,

and DVDs, and speaking engagements are all donated to charity.

I just want to do for your family what Pritikin did for my family.

But wait, isn't weight loss just about eating less and moving more?

I mean, isn't a calorie a calorie?

That's what the food industry wants you to think.

The notion that a calorie from one source is just as fattening

as any other is a trope broadcast by the food industry

as a way to absolve itself of culpability.

Coca-Cola itself even put an ad out there emphasizing

this “one simple common-sense fact.”

As the current and past chairs of the Harvard's nutrition department put it,

this “central argument” from industry is that the “overconsumption of calories

from carrots would be no different than the overconsumption of calories from soda”

If a calorie is just a calorie, why does it matter what we put in our mouths?

Let's explore that example of carrots versus Coca-Cola.

It's true that in a tightly controlled laboratory setting,

240 calories of carrots (10 carrots) would have the same effect

on calorie balance than the 240 calories in a bottle of Coke,

but this comparison falls flat on its face out in the real world.

You could chug those liquid candy calories in less than a minute,

but eating 240 calories of carrots would take you more than

two-and-a-half hours of sustained constant chewing.

Not only would your jaw get sore, but 240 calories of carrots

is like five cups—you might not even be able to fit them all in.

Our stomach is only so big.

Once we fill it up, stretch receptors

in our stomach wall tell us when we've had enough,

but different foods have different amounts of calories per stomachful.

Some foods have more calories per cup, per pound, per mouthful than others.

This is the concept of calorie density:

the number of calories in a given amount of food.

Three pounds is about what the average American eats in a day.

As you can see, for example, oil, is a high calorie density,

meaning a high calorie concentration, lots of calories packed into a small space, so

drizzling just a tablespoon of oil onto a dish adds over a hundred calories.

For those same calories, you could have instead eaten about

two cups of blackberries, for example, a food with a low calorie density.

So, these two meals have the same number of calories.

You could swig down that spoonful of oil

and not even feel anything in your stomach,

but eating a couple of cups of berries could start to fill you up.

That's why yes, biochemically a calorie is a calorie,

but eating the same amount of calories in different foods,

can have different effects.

The average human stomach can expand to fit about four cups of food;

so, a single stomachful of strawberry ice cream, for example,

could max out our caloric intake for the entire day.

For the same 2,000 calories, to get those same 2,000 calories

from strawberries themselves…

you'd have to eat 44 cups of berries.

That's 11 stomachfuls.

As delicious as berries are, I don't know if I could fill my stomach

to bursting 11 times a day.

Some foods are just impossible to overeat.

They're so low in calorie density, you just physically

couldn't eat enough to even maintain your weight.

In a lab, a calorie is a calorie, but in life, far from it.

Traditional weight-loss diets focus on decreasing portion size,

but we know these “eat less” approaches can leave people

feeling hungry and unsatisfied.

A more effective approach may be to shift the emphasis from restriction

to positive “eat more” messaging of increasing intake of healthy,

low-calorie-density foods, but you don't know, until you…

put it to the test.

Researchers in Hawaii tried putting people on more of a traditional,

Hawaiian diet with all the plant foods they could eat,

unlimited quantities of fruits, vegetables, whole grains, beans.

And, the study subjects lost an average of 17 pounds in just 21 days.

Calorie intake dropped by 40%, but not because they were eating less food.

They lost 17 pounds in three weeks eating more food,

in excess of four pounds a day.

How could that be?

Because whole plant foods tend to be so calorically dilute,

you can stuff yourself without getting the same kind of weight gain.

They lost 17 pounds in three weeks eating more food.

That's why in my upcoming new book, How Not to Diet,

which I am very excited about, [clears throat],

that's why “Low in Calorie Density” is on my list of the 17 ingredients

for an ideal weight loss diet.

As noted before, Americans appear to average about three pounds of food a day.

So, if you stuck with mostly these foods, you can see how you can eat more food

and still shed pounds.

A landmark study set to be published next month, found that

even when presented with the same number of calories,

and the same salt, sugar, fat, fiber and protein,

processed foods led to weight gain, two pounds gained over two weeks;

and unprocessed foods led to weight loss, two pounds down in the same two weeks.

Here's one of their processed food meals…

which is probably healthier, actually, than what most people eat.

Non-fat Greek yogurt, baked potato chips, sugar-free diet lemonade

with a turkey sandwich, has the same number of calories as this

what the unprocessed-meal-food folks were eating,

a kind of a southwest entrée salad with black beans, avocados, nuts…

that's the calorie density effect.

Same calories but there's just more food,

no wonder it satisfied their hunger.

And they ended up four pounds lighter in two weeks eating more food.

So, how can you decrease the calorie density of your diet?

Well, just a quick peek at the two extremes should suggest two methods:

abandon added fats and add abandoned vegetables.

Method number one: Covertly put people on a relatively low-fat diet,

and they tend to lose body fat every day even though

they can eat as much as they want.

But if you instead give those same people the same meals,

but this time sneak in enough extra fats and oils

to change it to a high-fat diet, they gain body fat every day.

In fact, in a famous prison experiment in Vermont,

lean inmates were overfed up to ten thousand calories a day

to try to experimentally make them fat.

This turned out to be surprisingly difficult.

Most starting dreading breakfast and involuntarily threw it up.

The researchers learned how difficult it was to have people gain weight

on purpose, unless... you feed them lots of fat.

To get prisoners to gain 30 pounds on a regular diet,

it took about 140,000 excess calories per certain amount of body surface area.

To get the same 30-pound weight gain just by adding fat to their diets,

all they had to do was feed them about an extra 40,000 calories.

When the extra calories were in the form of straight fat,

it took as many as a hundred thousand fewer calories

to gain the same amount of weight.

A calorie is not a calorie— it depends on what you eat.

In this case, lowering fat content effectively

made up to 100,000 calories, disappear.

That's why “Low in Added Fat” is on my list

of ideal weight loss ingredients as well.

There are, however, two important exceptions.

Processed foods with “reduced-fat claims” are often so packed with sugar

that they can have the same number of calories as a higher fat product.

SnackWell's fat-free cookies, for example, at 1700 calories

per pound are as calorie- dense as a cheese danish.

The other exception to the low-fat rule is that vegetables

are so calorically dilute that even a high-fat veggie dish,

like some oily broccoli with garlic sauce, tends to be less calorie dense

overall, which brings us to the second strategy for lowering calorie density:

instead of sneaking out fat, sneak in vegetables.

The biggest influence on calorie density is not fat, but water content.

Since water adds weight and bulk without adding calories,

the most calorie-dense foods and the most calorie-dense diets

tend to be those that are dry.

Some vegetables, on the other hand, are more than 95% water,

and not just iceberg lettuce.

Cucumbers, celery, turnips, cooked napa cabbage,

bok choy, summer squash, zucchini, bean sprouts, and bamboo shoots

can top out at 95% water.

They're basically just water in vegetable form.

A big bowl of water-rich vegetables is practically

just a big bowl of trapped water.

The effect on calorie density is so dramatic

the food industry wants in on the action.

They figure they could use nanotechnology

to “structure a solid processed food similar to a celery stalk

with self-assembled, water-filled,… nanocells or nanotubes.”

No need, as Mother Nature beat you to it.

When dozens of common foods, pitted head-to-head

for their ability to satiate appetites for hours,

the characteristic most predictive was not how little fat

or how much protein it had, but how much water it had.