Chances are, you didn't notice the first time Gary Taubes rocked your world. It was 2002. Taubes, an award-winning science journalist, wrote a cover story for The New York Times Magazine called "What if It's All Been a Big Fat Lie?" The article was a follow-up to one published the previous year in Science magazine, called "The Soft Science of Dietary Fat."

Those two articles were so controversial, and so widely discussed, that they eventually led to a distinct shift in the way the media covered nutrition and weight loss, and the way the public talked about it.

Taubes scored a major book deal, and spent the next five years researching the science behind our commonly held ideas about nutrition, obesity, and public health.

What happened between 2002 and 2007 is instructive: Thanks in part to the new legitimacy bestowed upon low-carb diets by Taubes' articles, Dr. Robert Atkins' books sold by the millions. Some restaurants stopped serving bread with meals, and nobody had to apologize for ordering the juiciest steak on the menu. In 2003, during the same week that Atkins slipped on a patch of ice and suffered a fatal head injury, another low-carb book, The South Beach Diet, arrived in bookstores. That one was soon selling more than 100,000 copies a week.

While Taubes studied nutritional science from every angle, deploying a team of researchers to libraries across the U.S., the low-carb craze came and went. That helps explain why Good Calories, Bad Calories, which came out to mixed reviews in 2007, never got the attention it deserved. The battles over carbs and fat had all been fought, and the media was bored and ready to move on. (It helped that the media had a new star in journalist Michael Pollan, who published The Omnivore's Dilemma in 2006 and In Defense of Food in 2008. The latter book quotes Taubes extensively.)

After my first interview with Gary, I immediately put his advice into action. In 6 weeks I went from 198 to 203 while my waist shrunk by an inch! I didn't change anything in my workouts. (More about what I changed later.) Obviously, Gary was worth a second interview.

I caught up with the 53-year-old Taubes, who started out as a physicist with degrees from Harvard and Stanford before he turned to science writing, for a telephone interview.

You started out writing on stuff like rocket science. How did you first get interested in obesity and public health?

eat all you want

Well, after I finished my first book, Bad Science, on the cold fusion nonsense in Utah, some of my physicist friends said to me, "If you like writing about bad science, you should check out public health. You'll have a field day."

So I started writing about public health, and it turns out the science was pretty universally terrible. I did a story for Science magazine, in which I spent a year on the controversy over whether dietary salt causes high blood pressure. One of the worst scientists I ever interviewed — and I had interviewed some really terrible scientists in my life — took credit for getting Americans not only to eat less salt, but also to eat less fat and less eggs.

I literally put the phone down when I was done with the interview, called up my editor, and said one of the five worst scientists I've ever interviewed took credit for getting Americans to eat less fat and less eggs. I don't know what the story is with fat and eggs, but if this guy was involved in any substantive way, then there's a good story.

After I finished the salt story, I spent a year reporting a story on how we came to believe that low-fat diets are good for us. Again, the science behind it was pretty universally terrible. And that led me to do The New York Times Magazine story.

They wanted me to do a story for the magazine where we try to figure out what caused the obesity epidemic, because you could localize it in time. Basically, some time from the late 1970s to the early 1980s, obesity in America started shooting upward.

There were two hypotheses. One said high-fructose corn syrup was to blame, but that didn't really pan out. Its bad stuff, but it's not the cause of the epidemic.

But this other idea, that the low-fat doctrine was to blame, was interesting because I came upon these five studies that had been done, but not yet published, on the Atkins Diet. They put people on a high-fat Atkins Diet, and compared them to people put on a low-fat, low-calorie, American Heart Association-type diet. And not only did the people on the Atkins diet lose more weight — even though you're not telling them to eat less — they also had better cholesterol profiles.

Let's get to the most controversial point: You say that eating extra calories won't make people fat.

The assumption that fat tissue isn't regulated at all is almost naive beyond belief. Every other part of the human body is well regulated, but fat tissue is just this garbage can that all these empty extra calories get dumped into. And it just happily expands, despite having these deleterious effects all over your body.

The idea of homeostasis, where you want to keep the internal environment stable regardless of what else is happening, was first discussed in the 1860s by a French scientist named Claude Bernard. Are our fat cells somehow exempt from this?

As you get fatter, homeostasis gets thrown out of whack, because among other things, fat is a good insulator. So your body starts getting hotter. Now you have to cool it down in ways you didn't have to before. You start sweating, and when you lose body fluids, the salt content in the blood gets higher. All kinds of things start going awry when you start getting fatter.

It makes absolutely no sense that your fat tissue wouldn't be regulated, and yet these people believe that obesity is all about calories.

If you look at animals, all animals regulate their fat tissue very carefully. You can't just force animals to overeat and make them fat.

Really?

They won't do it. The only animals that will get fat by dietary means are very carefully bred rats in laboratories, and house pets that don't eat the foods they evolved to eat.

If you've ever looked at cat food, it's packed with carbohydrates. And yet cats are carnivores in the wild. Felines don't eat carbohydrates. They eat meat. That's what they do. And yet we take then into our homes, we feed them carbohydrates, and lo and behold, they get fat.

The argument I'm making is that [obesity is] a disorder of excess fat accumulation, not of sloth and gluttony. Overeating is the side effect of the disorder, not the cause. What you want to know is, what regulates fat accumulation?

This sounds like some sort of semantics game. Isn't the problem just that they were overeating?

Yao Ming

Yao Ming has been growing for much of his life. Until he got to 7 feet, 6 inches, he was in positive energy balance. He was overeating. Nobody considers his height to have been caused by overeating.

He was secreting growth hormone, and that also prompted the secretion of something called insulin-like growth factor, and those things made his bones extend and his muscles extend. He got heavier and heavier because he was getting bigger, but he didn't get bigger because he was overeating. He was overeating because he was getting bigger. He was getting bigger because he was secreting hormones.

So if you're talking about growth, all you care about are what hormones and enzymes control growth. As soon as you get into fat tissue and horizontal growth instead of vertical growth, suddenly the causality slips. Hormones and regulation go out the window, and now overeating is the problem. Instead of a metabolic defect, which the research clearly points to, we assume that it's a character defect.

So what's regulating the growth of the fat tissue?

The answer, which we've known since the early 1960's, is insulin. Insulin is the hormone that primarily regulates fat accumulation. If you want to get fat out of your fat tissue, you have to lower your insulin levels.

And insulin is regulated for all intents and purposes by the carbohydrates in our diet. That's the simplest possible hypothesis. The physicist would call it "the zero-order approximation."

Other hormones play roles, and most of them work to get fat out of the fat tissue, but they can't do it if insulin levels are elevated. Adrenaline, growth hormones, all these things work to make you leaner, but they don't work if insulin levels are elevated.

And this has never been controversial. That's the weird thing.

That's never been controversial?

No.

That carbohydrates make you fat?

Well, that insulin makes you accumulate fat, and that carbohydrates regulate insulin levels.

People don't just put those two ideas together?

good calories

Nobody puts them together because they don't like the conclusions.

Everything that we believe about obesity basically came out of the 1970's. This was a period in which a half a dozen men completely dominated the field. So they controlled what everybody was allowed to think.

They wrote all the textbooks. Every textbook on obesity that isn't about behavioral therapy was written by one of these six men. Well, actually only two guys wrote the textbooks, which were often accumulations of chapters written by different people. So they would invite one of these other six to write the relevant chapters.

In a textbook on obesity, you'd have a chapter on dietary therapy. That chapter would always be written by the same guy: Ted Van Itallie. A very nice guy. I've interviewed him. What he believed became what everyone believed. As these guys started to retire, in the 1980's, their protégés took over.

These guys would also host the conferences, and then they would write up the conference proceedings. So they would take what was presented in the conference and they would filter it into what they believed was true.

For instance, in 1973 the National Institute of Health had its first-ever conference on obesity, and there were two talks on dietary therapy. One was about the effectiveness of fasting, and the other was about the unnatural effectiveness of carbohydrate-restricted diets by Charlotte Young, this very well respected nutritionist from Cornell.

She talked about how weirdly effective these diets are at lowering weight, and doing it without making the subjects hungry. In her own laboratory she tested diets of 1,800 calories [per day] on young, overweight men. She kept the protein content the same, but had progressively lower levels of carbohydrates and higher levels of fat. The less carbohydrates, the greater the weight loss, [even with] the same amount of protein and the same calories.

But the guys who put the conference together, George Bray and George Cahill, believed that obesity was all about gluttony and sloth, and that it didn't matter what kind of calories you ate. So when they wrote the conference proceedings, and specified for the National Institute of Health how money should be spent and what areas should be studied, they said the reason low-carb diets work is because they restrict calories. This was the exact opposite of what Charlotte Young had said.

This went on over and over again.

Everybody reading this knows somebody who has eaten a whole lot less, exercised a whole lot more, and lost a lot of weight. How do you explain that?

There are two ways. One is you can starve people like on The Biggest Loser. You can get them to work out three hours a day. You can force them to lose weight by forcing them to be in negative energy balance. But as soon as they go back to eating they'll regain the weight. And not only that, they'll regain the weight faster than they lost it.

People have done studies of starvation or semi-starvation where they put people on 1,600-calories-a-day diets. They lose weight, but they're hungry all the time. When you go back to overfeeding them — 3,000 or 4,000 calories a day — they're still constantly hungry, even though they're eating two to three times the food they were eating before. They put the weight back incredibly quickly, and it's almost all fat.

So they would end up fatter.

They're fatter after they've been re-fed than they were before they started the semi-starvation diet, and they regain the weight far faster than they lose it. It takes maybe three, four, or six months of semi-starvation to lose 25% of your body fat, but you can gain it back in six weeks. It's like their bodies just inflate, you know, and they're hungry all the time. So even though they go back to eating 3,000 to 4,000 calories a day, they're still hungry.

I've spoken to people who were on The Biggest Loser, and all those people gained the weight back.

All the contestants?

Yeah, because they can't live in a state of constant hunger. Well, some people can do it long-term, but they're rare examples. Their whole life is basically dedicated to living with hunger. And I think eventually what happens is their body changes so they become, in effect, anorexic. But that's speculation.

So what about the other option?

The other people go on a diet, they eat less, they exercise more, they lose weight, and they keep it off. There are people who do that. The point I would make is that when you go on a diet, even if it's Dean Ornish's 10% fat diet, among the things that you give up are sweets, high-glycemic-index carbs, starches, and white flour.

If you drink beer regularly, you either give up the beer, or you switch to light beer. If you drink a lot of Coca-Cola or Pepsi, you drink Diet Coke or Diet Pepsi. So in the process of cutting calories, you also cut out carbohydrates. It's virtually impossible, mathematically, to cut your calories significantly without cutting carbohydrates, because carbohydrates are such a huge part of the diet.

Thanks for your time. How can people get in touch with you?

It's always a pleasure Josef. As you know — and get on me about — I don't have a blog or anything, but if people want more, my book is a good start.

Addendum

I cut out all fruit from my diet, but allowed myself as much fat and protein as I felt like eating, which meant more calories, lots more calories. Regular bacon became my new best friend, much to my Jewish fiancé's dismay. And, as stated, I went from 198 pounds to 203 pounds in six weeks, while my waist shrunk by an inch!