A Tough Problem

Wednesday, September 22, 2010

Dear Uncle Gus,

You mentioned starting [Gary Taubes's] Good Calories, Bad Calories, and commented about the early sections on government-sponsored research. If you've finished the book, has it changed the way you think about diet etc. too? If so, in what way?


Bill Banting

Dear Bill,

As I noted at the time, I was dubious about being able to finish the book any time soon, and was undecided about whether I would discuss it any further here. I was right about the first and now know the answer to the second. I haven't touched that tome since, due to personal and professional obligations, and it may be a while -- as in well after the holidays -- before I do.

That said, I can still answer your question in some respects. Although nutrition is not my field, I am a bioscientist with training and work experience in another interdisciplinary area. As such, I appreciate both the difficulties scientists encounter as they work within their own fields and the further challenges of building on work in fields not one's own.

Contrary to media portrayals, science is hard and, often, messy work. Furthermore, science doesn't always immediately answer questions, and sometimes takes forever to even start zeroing in on the answers. The early sections of the book do a decent job of illustrating this.

So, while the government has interfered greatly in the investigation of human nutritional requirements, it doesn't deserve all the blame for the fact that they haven't been completely pinned down yet. The problem itself is difficult, and answering it definitively will require work in multiple fields to yield reliable information.

I regard the difficulty of answering that question as being on a par with answering the question of whether human activity causes global warming. Regarding the formulation of complex theories, I recall that Amit Ghate once linked to an excellent example, written for laymen, of what it would take to show definitely that human activity causes global warming. I think nutritionists face a similar degree of difficulty in determining human dietary requirements, perhaps including establishing what traditional foods may be dangerous and why.

It is here that I am pretty sure that I will take issue with Taubes, for he starts outlining a positive argument of his own. I think he offers good evidence that something about traditional Western diets is probably involved in causing a variety of illnesses, just as it is there is evidence that the overall temperature of the world's climate has been increasing in recent history. But why? For reasons I will not get into here -- in part because I haven't read his whole argument and in part because I doubt part of what I have read -- I am so far not buying his explanation.

So, in the sense that I have always regarded nutrition as a difficult science, Taubes hasn't changed how I think about nutrition, except to confirm that view. He has certainly given me a greater appreciation for what might need to be done to advance the field to the point that it can offer reliable advice. In doing that, he has shown me that there may well be a light at the end of that tunnel. Indirectly, because of his work, I know of a few things to keep an antenna up about. In that respect, you could say he has changed my mind. But this leads me to the following...

Suppose, for the sake of argument, that I did completely or substantially agree with Taubes after I read his book. Should I change my diet? This is where things get really interesting to me. I have noticed that Objectivists who have read this book fall out into two general camps. Some make major changes to their diet shortly thereafter and some do not.

I suspect that members of the former group are more influenced by Taubes's discussion of "diseases of civilization" and (naturally) want to avoid them. Conversely, it appears to me that those in the latter group (which will probably include me), are more impressed with Taubes's observation that bad nutritional advice can be worse than none at all. (Other personal variables, of course, are superimposed on this, like whether one has health issues possibly related to diet and what one's diet actually is to begin with.)

So, should I make major changes to my diet based on the reading of one book, assuming, again, that I mostly agreed with it? (Please note that I do not assume that people who change their diets soon after reading the book have limited their reading to just it.) Plainly not, any more than I fully agreed (or should have) with Ayn Rand after I first read (just) Philosophy: Who Needs It. Any one book doesn't (and can't) contain the sum of human knowledge about any given discipline. But in considering your question, I have noticed that there is an important difference between philosophical guidance and non-philosophical guidance that is worth bearing in mind.

Philosophy is more difficult to think about than other disciplines in terms of being much more highly conceptual, but it is easier to think about than any in terms of the availability of data: Everything you know about is potentially useful in evaluating philosophical arguments, and nobody needs specialized training or data to progress. For example, if you aren't familiar enough with the concretes pertinent to a given philosophical question, you can, if you are careful, find other concretes that you are familiar with and make good progress. Any ordinary, reasonably well-educated person can, with sufficient persistence and no specialized training, understand and evaluate a philosophical argument -- and without having to read vast quantities of specialized literature at that.

That situation is reversed in other disciplines, particularly in the sciences. Practically all the data Taubes presented regarding how the addition of refined carbohydrates and processed grains coincided with increased rates of certain diseases in several populations, for example, was news to me. Assuming causation, you would have to have that specific type of data to formulate, let alone evaluate, a theory of "diseases of civilization." You would need to be sure that the data were collected properly in each study before you could even get to the question of how to interpret it. And, to interpret such data, one would need knowledge of (at least) biological, medical, and statistical methods. On top of all that, there may be data -- already discovered or yet to be discovered -- you haven't even considered that has a bearing on your question.

The last time I mentioned this book, someone put in a good word for Taubes's honesty. I never questioned Taubes's honesty, and the fact remains that the most honest person on earth can make any number of mistakes along the way of formulating such a hypothesis. This is why -- even without the government mis-allocating research funds -- enormous literatures would still exist in the sciences as workers found new data and interpreted what it meant according to their (often) very different theories. I feel reasonably sure, without even having looked, that for all its footnotes, Taubes's book is not a comprehensive review of any of the relevant scientific literatures. (Please correct me if I am wrong.) Nothing in this paragraph is intended in any way as a slight to the hard work Taubes did.

So, in evaluating a non-philosophical argument, one often has much less recourse to preexisting data or other knowledge, and may need to obtain special training -- or consult someone with such training. Knowing this, I can safely say that even if I agree with Taubes's argument by the end of his book, I will not (immediately) change my mind: At the end of the day, that book remains one man's best interpretation (including honest errors) of the specialized data and knowledge he had at his disposal when he wrote it. It is, therefore, frequently of paramount importance in evaluating an argument in a specialized field to seek out the opinions of dissenters in that field.

Having said all this, my observations about how Objectivists react differently to this book, as well as how different people reach conclusions about the causes of global warming, have given me a keen appreciation for a very important problem: We can't all be specialists in every field. We all, at one point or another, end up having to delegate part of the mental labor in such fields to others.

Knowing whom to rely on in fairly well-established fields, such as medicine or architecture, is fairly easy, and not too difficult to reassess from time to time. It is not so straightforward in new fields that are in flux, like nutrition, psychology, or the science of climate. (Indeed, if a field is new enough, it is legitimate to ask whether it can offer much valuable guidance at all.) This is true for reasons that have, more often than not, nothing whatsoever to do with the moral character or even the competence of the potential delegatee.

-- CAV

If you'd like to ask a question, just type it into the box at the upper right labeled, "Ask Uncle Gus."

Note: Although I am a scientist, I regard myself as a layman in the field of nutrition. As such, I will not offer nutritional advice or further comment on any particular theory of nutrition here.


Today: (1) Minor edits. (2) Added a note.

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