This week, a new documentary about the obesity crisis premieres on HBO. It’s called “Weight of the Nation”. And it’s take-home message is wrong, wrong, wrong.

You’ll be hearing a lot about this documentary, if you haven’t already. And with good reason. It’s the result of an unprecedented collaboration between the three major public-health institutions in America:

1. the nonprofit Institute of Medicine (IOM)
2. the CDC (Centers of Disease Control and Prevention)
3. the NIH (National Institutes of Health)

“Weight of the Nation” is a sincere attempt to confront an epidemic (obesity) that costs the US alone 147 billion (in 2008, up from 78.5 billion in 1998).

“Obesity, and with it, diabetes are the only major health problems that are getting worse in this country, and they’re getting worse rapidly”, said CDC Director Thomas Frieden, MD, MPH, in a July 27 media briefing during the Weight of the Nation Conference. “Beyond the economic costs are the disability, the suffering and the early deaths caused by obesity”, he added.

Yet the documentary—made by sincere and well-meaning people, mind you- draws the wrong conclusion and sends the wrong message. And it’s unlikely to make the slightest bit of difference in the obesity crisis because its focus is on the wrong enemy.

Here’s why. For decades we’ve been being told that the reason we’re so fat is that we eat too much and we exercise too little. This diagnosis is so widely accepted that to question it makes you a heretic. We’ve variously blamed high-fat foods, saturated fat, too much protein and sedentary lifestyles for this situation, but what we haven’t blamed is the real cause of the problem:

Carbohydrate intolerance and a toxic diet.

The conventional wisdom is that we were never fatter, but the truth is we were fat during the depression, when bread lines and soup kitchens dotted the nation. As Gary Taubes asks in his superb Newsweek cover article The New Obesity Campaigns Have it All Wrong, “How can we blame the obesity epidemic on gluttony and sloth if we easily find epidemics of obesity throughout the past century in populations that barely had food to survive and had to work hard to earn it?”

When you get real close to it, even the common idea that we’re fat because we don’t exercise doesn’t pass the smell test. “Why is the world full of obese individuals who exercise regularly?” asks Taubes. Indeed. The Weight of the Nation shows construction workers in Arkansas laboring at back-breaking jobs that involve running up ladders with the equivalent of a 50 pound backpack, and lifting very heavy stuff all day long. If it were all about exercise, guys like this should be svelte.

They’re not.

And if it were all about eating too many calories, how do you explain the fact that some medications have as a “side effect” weight gain of anywhere from 20-140 pounds? Did the folks who gained that weight on the meds all of a sudden start eating twice as much?

No.

The fact is that weight gain is driven by hormones, and the most important hormone for weight gain—insulin- is driven by the engine of carbohydrates. It’s not that we’re eating too many calories (though that may be a part of the problem). And it’s not that we’re not exercising— (that is a huge problem, but not just from the point of view of weight).

The problem is that we’re eating too many carbohydrates. And the ones we’re eating are all the wrong ones.

We’ve been blaming fat (especially saturated fat) for years. Our health “authorities” have been promoting for decades what one writer called “the greatest nutritional experiment in history”—a high carbohydrate low fat diet. This grain- and carb-heavy diet—very similar to what’s used to fatten cattle—was best illustrated by the god-awful, thankfully discredited USDA food pyramid of 1992. (Your tax dollars subsidize the production of the very foods that are making us fat and sick, in the form of a corporate giveaway known as the Farm Bill.)

And of course, all these wonderful foods, made from corn, sugar and wheat, are virtually “fat-free”, so surely they’re healthy, right?

But fat was never the enemy, though acting as if it were made a lot of companies a lot of money.

The real enemy was- and is—sugar.

In the 1980’s, the FDA decided- in its infinite wisdom—that sugar was perfectly OK since the evidence against it “wasn’t conclusive”. (If you think this decision wasn’t influenced by the sugar lobby, I’d like to talk to you about a lovely bridge I have for sale in beautiful Brooklyn.)

“While the government spent hundreds of millions trying to prove that salt and saturated fat are bad for our health, it spent virtually nothing on sugar”, writes Taubes. “Had it targeted sugar then…our entire food culture….might have changed”.

And maybe we might have been told that the real culprits in our diet are not  meat* and saturated fat, but the overwhelming amount of sugar and processed carbs that we consume on a daily basis, and that are increasingly being linked to diabetes, cancer, Alzheimer’s and virtually every other disease of aging.**(Note that when I say “meat” isn’t to blame, I’m talking about pasture-raised meat, not the crap we get in supermarkets and restaurants.)

Meanwhile, we have a lot of very overweight people who not only suffer with their weight, but have the added indignity of being blamed for not having any “willpower”.

“Lack of will isn’t their problem”, says Taubes. “It’s the absence of advice that might actually work.”