Dave’s conclusions are orthogonal to mine and to Parker Pope’s, which are, as Dave notes, orthogonal to each other. My conclusions, Dave writes, left “the majority of frontline obesity researchers gritting their teeth.” Parker Pope’s apparently left a majority pronouncing her “main thesis — that sustaining weight loss is nearly impossible — dead wrong, and misleading in a way that could seriously, if indirectly, damage the health of millions of people.”

So how are we to make sense of a situation when thoughtful investigations of controversial subjects not only disagree with the conventional wisdom—what the majority of front-line researchers are said to believe—but with each other? Why does this happen? How do we cover it as journalists and interpret it as critical readers? I’ll continue to use obesity and weight loss as the case study here because it is now the subject that I (arguably) know best and it’s at the heart of Dave’s article.

One obvious explanation for the rise of personal health journalism, particularly on the subject of weight loss, is because obesity seems to be such an intractable problem on a personal level. If sustaining significant weight loss was not at least exceedingly difficult—a subject we’ll discuss shortly as it’s central to Dave’s argument—the plethora of books and articles suggesting easy fixes or never-before-tried fixes would be unnecessary. New diet books come along every day because the old books have, at the very least, outlived their usefulness. And because obesity is now such a critical societal problem, effecting the long term viability of our healthcare system and perhaps our economy itself, it’s not unusual these days to even have economists and circuit court judges speculating publicly about its cause and the best means of prevention.

In the late 1950s, less than one in eight Americans were obese, and fewer than 200 articles were published yearly on obesity in the English language medical literature. Today, more than one in three Americans are obese, more than 15,000 relevant articles were published in the academic literature last year alone, and the cost of obesity to the health care system in the US is estimated at $150 billion a year. These numbers alone suggest a research pursuit in turmoil, and a subject that should be ripe for journalistic investigation (and venal exploitation as well). If the conventional wisdom on the subject is correct—if all we have to do to lose weight is eat less and exercise more—then why so much research, and why are so many of us fat, and why so many more now than fifty years ago? And, if it’s not correct, then why not?

The articles by Dave, Parker Pope and myself are all attempts to answer these questions and to make sense of what Dave calls the main thesis of Parker Pope’s article, which he declares dead wrong: that weight loss is nearly impossible to sustain and so obesity is indeed an intractable condition. We’re sifting the evidence in different ways, approaching it from different perspectives, and coming to different conclusions. If the main thesis wasn’t at least mostly right, though, despite Dave’s claim to the contrary, none of us would need to write about this at all, and a over a third of the US population would not be considered clinically obese.

Because Dave, Parker Pope, and I take different approaches to the problem, the evidence we consider meaningful—and, of course, not all of it is, and perhaps not even most of it—is naturally different as well. Parker Pope argues that obesity is intractable based on common sense and some small, very well controlled studies (a fundamental requirement of good science). She concludes that that once we get obese, we’re pretty much stuck and public health advice and discussion should reflect that. She is implicitly challenging the kind of anecdotal accounts evoked by Dave himself (“most of us know people—friends, family members, colleagues—who have lost weight and kept it off for years by changing the way they eat and boosting their physical activity”) to make the argument that all it takes to be significantly less obese and stay that way is the right kind of behavioral modification and, well, maybe sufficient will power as well.

I agree with Parker Pope’s assessment about the intractability of obesity, but I argue that this is a product not so much of how the human body responds to weight loss but how it responds to the methods used to achieve that weight loss. I argued in my New York Times Magazine article that the old advice not to eat carbohydrates (refined grains and sugars, in particular) may have been the right advice and that these carbohydrates might be the fundamental causes of obesity.

Gary Taubes is co-founder of the Nutrition Science Initiative, and the author of Why We Get Fat and What to Do About It (Knopf 2010) and Good Calories, Bad Calories (Knopf 2007). He’s a contributing correspondent for the journal Science, and the only print journalist to win the Science in Society Journalism Award of the National Association of Science Writers three times.