Gary Taubes, Food Science Author, Answers Your Questions (LIVE Q&A)

There's no getting around it: obesity in the United States has steadily been increasing over the past twenty years. And it's a problem that seems to be getting worse every year.

In his new book Why We Get Fat: And What to Do About It, writer Gary Taubes investigates what makes us gain weight, concluding that a low-carb diet is best for healthy living. In New York Times Magazine, Taubes recently examined the growing evidence that indicates sugar is toxic.

Taubes comes from a science background, having studied applied physics and aerospace engineering Harvard and Stanford, before he earned a master's in journalism at Columbia. Taubes originally wrote mostly about physics issues, his focus has turned recently to health and nutrition.

Today, from 2:30 to 3:30 EST, Gary is here to answer any questions you might have about America's weight problem, nutrition, his book, and his recent article on sugar. If you want to ask Gary a question, leave a comment or tweet your question under the hashtag #FatChat.

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04/20/2011 3:34 PM EDT

Thank you

It's been fun, everyone. Thanks for the questions and caring enough to ask them!

-Gary Taubes

04/20/2011 3:30 PM EDT

From science to food

runongreen asks via the comments:

What changed your interest from applied physics to nutrition?

I became a journalist, which was the first switch, and got obsessed with good science and bad science. Lived at a physics lab for a year and watched some very bright physicists screw up an experiment and discover non-existent elementary particles.

I wrote a book about cold fusion, one of the great scientific screw-ups of the last century. Then some of my physics friends said to me, if you think the science in cold fusion was bad, you should look at some of this stuff in public health.

One thing led to another and the next thing I knew I was looking at the science underlying some of our core beliefs in nutrition -- that salt consumption leads to high blood pressure, fat consumption to heart disease, etc. That science was indeed terrible and now I'm trapped in this world of trying to set it straight. (Assuming, of course, that I'm right and the CW is indeed wrong.)

04/20/2011 3:23 PM EDT

Dangers of more protein and fats?

Matt Reid asks via the comments:

When stories like mine emerge are they a detriment to your studies because the conversati­on can be quickly turned into fad diets and weight loss rather than health and true science?

And lt11481 asks via the comments:

If I am avoiding carbs and thus eating more protein and fats, what does this do to my level of coronary risk?

Thanks for the comments, guys. And, no I think anecdotal evidence of the kind you're giving can be valuable in convincing medical authorities that there's something meaningful here.

A key point I make in "Why We Get Fat" is that an obese or overweight individual needs a lot of calories to run their body, so that the only thing they should be restricting are the carbohydrates that make them fat -- the sugars, refined carbs, starches. If they do this and keep calories high, then they're eating a lot of fat and now it all sounds suspiciously like the Atkins diet.

The catch is Atkins was a smart guy and just happened to get it right (most of it, anyway). If you have fears about that the fat is doing to your heart disease risk, get a lipid profile done -- including what's called a VAP test. I just did (my wife insisted on it) and posted it on my blog . You can see what yours is very likely to look like, since I also eat like you both say you do.

04/20/2011 3:14 PM EDT

Sugar calorie intake?

Ronan Freyne (@Ronanfreyne) asks via Twitter:

What % of calorie intake do you think is generally okay to get from sugar?

You mean, other than the lower the better? I don't know. One of the amusing/interesting facts I came upon in my research was a British physician in the early 1700s or 1800s (forget which) defending sugar in the diet, but commenting that it does indeed make women fat. And this would have been at a time that sugar consumption was perhaps one tenth what it is today.

Now getting fat and getting sick (diabetes, cancer, etc.) are two different things. One South African diabetes specialist in the 1950s, suggested that over about half the sugar we consume today, you start to see high rates of diabetes in populations. But the numbers are confusing because of how he was calculating sugar consumption compared to how the USDA does, etc.

So, keep it low. That's all I can say for sure.

04/20/2011 3:10 PM EDT

Why is it everyone gets it wrong?

vikingv has this to say via the comments:

Labeling a high carb as unhealthy and a low carb diet as healthy is not correct.

Hmmmm, not reading my books, but attacking straw men. Two factors seem relevant to me: glycemic index and fructose content. So as I say in Why We Get Fat, some carbs are fattening some are not. Sugars are probably the worst because of their effect on insulin resistance and the liver. Easily digestible starches and refined cars are problematic because of the insulin response needed to handle them. Green vegetables -- fine.

Low carb content, lots of fiber to slow down digestion. But, but but but, all people aren't the same. Someone who is naturally lean is someone who can tolerate the carbs and sugars in the diet (at least their weight can). These people are different than those of us who put on weight easily. So a carb content that seems fine for a lean person could easily be the cause of obesity and even massive obesity in someone who's sensitive to the carbs in the diet.

So yes, spaghetti and spinach, not the same, and if you think I said they were, you should read my books.

04/20/2011 3:04 PM EDT

Whole grains

Elizabeth Popp asks via the comments:

What is your recommenda­tion for eating whole grains as a part of the total diet? How would we know if or when we become insulin resistant? Do we cut down on whole grain carbs when we gain weight, or is there another indicator that we can watch?

The first thing I'd do is get rid of the sugars entirely, but the second thing I'd do is get rid of the other refined carbohydrates and starches. Shill alert: I discuss this at length in my book "Why We Get Fat" and if you're overweight or obese, I recommend you read it.

04/20/2011 3:00 PM EDT

Splenda or sugar?

BrainyLegume asks via the comments:

Which is worse: Splenda or sugar? I know Splenda is not good, but I'm kind of addicted..­.

Ok. Splenda v. sugar, I'd go with splenda, but that's because I know the problems with sugar (or at least think I do). As for how do you know you're insulin resistance, a good sign is if

1). You're getting fatter, 2). your triglycerides are high and your HDL is low. High blood pressure is another sign of insulin resistance.

04/20/2011 2:53 PM EDT

Is food coloring toxic?

Is food coloring toxic? I thought I read about Europe tightening regs on the use of color additives.

Another one I can't answer. One way I've found to keep credibility (such as it is) is to speak out only about those subjects on which I've done significant research. That said, the point of my books is that there are very well defined chronic diseases of western diets -- obesity, diabetes, heart disease, cancer, etc. -- that can be linked to the consumption of sugar and other refined carbohydrates and are all associated with insulin signaling and insulin resistance.

If food coloring was toxic, it's hard to know what diseases it would be causing. And one thing I discuss specifically in my book "Why We Get Fat" is that there were plenty of populations with high levels of obesity and diabetes that wouldn't have been consuming artificially colored foods, so those would stand as counter-examples to the idea that food coloring causes those disorders, at least. Key thing to know about science is that we want to explain observations. If food coloring was toxic, which it could be, we need to have some diseases that it could be causing. Without the latter information, the former hypothesis doesn't do much good.

04/20/2011 2:37 PM EDT

Is agave a smart sugar substitute?

Another good question from @CurlyKarin via Twitter:

Is agave a smart sugar substitute?

Agave has a very high fructose content -- perhaps over 90 percent. That suggests it could be worse than sucrose or HFCS, although it gets complicated. The glucose in these sugars stimulate insulin secretion and that affects how the liver deals with the fructose and vice verse. So having less glucose could be beneficial, while having more fructose could be worse. I'd vote for worse, but that's just speculation.

04/20/2011 2:31 PM EDT

What about aspartame?

@CurlyKarin asks via Twitter:

Is aspartame really that bad for me (even in moderation)?

I wish I knew. I had time to research sugar and other carbs excessively. Little time to research artificial sweeteners. My next topic, perhaps.