habeas verum corpus

by the other theo

Though I am sometimes rather insecure about it, having lost over 30 pounds and mostly kept it off means that I am someone who has done a somewhat rare thing: I transformed by body and made the changes stick.

I have an online friend who has transformed herself in the last few years too.   She got in shape and just ran her first marathon earlier this year after a long period of dealing with health problems that made fitness difficult.

So when she mentioned that a book named Body Of Truth by Harriet Brown was one of the most important books about nutrition and weight that she’d read in 2015, I thought I should give it a look.    Looking at the dust jacket, the book purports to be about “How Science, History, and Culture Drive OUR OBSESSION WITH WEIGHT — and What We Can Do About It”.    That certainly sounded interesting… an exploration of how modern food production in the 20th century, cultural concepts of beauty, and ideas of food science interacted to produce a society forever striving to be thinner seemed like fertile ground for important discussion.

The book is all that to some degree or another, but with a much more immediate and personal focus from the author.  She’s a woman who battled with food most of her life, and watched her daughter battle with serious anorexia as a teen.   This is a woman for whom simple scolding about weight and talk of the latest fad diets will not produce any kind of sympathetic reaction.   She’s fairly up front about this, which is good, because her personal experiences and attitudes very much drive the content and tone of the book.

The thesis of her book can be boiled down to a few sentences:  social and medical attitudes about weight loss are causing real hurt in America today.   Calling someone fat is considered to be a horrible insult by many people, possibly the worst insult that can be made, but the insult is spoken everywhere.  It is synonymous with physical and moral weakness, laziness, and turpitude.   It is as if, after the Sexual Revolution, society took all the prudery once reserved for sex and transferred it to food.    It also says that science and medicine jumped into this morass and offered little in the way of effective solutions.   Diets, at least in the popular sense, do not work long term.  Shame is causing harm, even to the point that some doctors appear to attribute their patient’s maladies simply to being “fat” or “overweight” without looking further.  Drugs and operations are drastic solutions whose long term outcomes are not well understood.    There needs to be another way.

If all this sounds provocative, it is also well-documented.   Within a book of just less than 250 pages; aside from footnotes, there are 36 pages reserved for additional end notes and a selected bibliography.  Ms. Brown has done her homework, collected research, done primary source interviews, and notated pretty much everything.

Yet for all that, I do take some issue with her approach:

  • She seems to lament the weakness of the scientific results, but she does fully state that those weak results are due to the nature of statistical analyses.   Statistics can point at a “what” but rarely describe a “how”.  The health science behind smoking is an illustrative case.   Statistical studies showed that smokers had much higher incidence of cancer, emphysema, and heart disease than non-smokers.  These conditions killed people.  That showed what was happening, which was an important public health reason to suggest that people don’t smoke.  It said nothing about why smoking caused any of those conditions (which turned out to combination of things — tar clogs the lungs, nicotene and carbon monoxide stress the heart.)  It was also a very strong result and was easy to separate the signal from the noise.  Nutrition is a more subtle problem where it’s much harder to separate signal from noise.  Everyone eats.  It’s impractical to put large numbers of people on controlled diets for a long time.  That makes the “what” harder to detect.  So, it would be useful to know more about the “how” in order to judge how big the “what” is.  Statistics don’t provide that answer.
  • She tends to paint some legitimate science questions as silly.  She spends the first couple of chapters of the book discussing the statistical relationships between weight and life expectancy.   She sets up a hero in Katherine Flegal, whose research shows that there is little in the way of connection between BMI and life expectancy.   She also creates a number of villains, including one of Flegal’s frequent critics, Walter Willet.   Willet’s research produces a result that is opposite to that of Flegal, and Brown faults Willet for deleting “not only anyone who every smoked but also anyone with a history of cancer or heart disease, ultimately eliminating nearly 80 percent of the deaths” in the data sets he uses as a source for his research.   The way that Brown initially puts it, that deletion makes no sense and makes her point.   As someone trained in science, I see it a little differently. If you want to understand the seriousness of the effect of BMI on health, you want to eliminate people who are dying from other obvious causes — causes that have little or nothing to do with BMI — from your study.   If a lot people are dying from heart disease, cancer, or smoking-related health problems by some age (say 40), that could be masking deaths due to BMI-related health problems by a later age (say 50.)   That makes BMI-related health issues something that happens later but possibly not less severe when it hits.  Brown uses other researchers to eventually bring some of that point out, but it also makes Willet sound illogical and arbitrary on a point that is a legitimate scientific question.
  • She also complains more than once that researchers like Willet seem to show a lot of ego and treat all this rather personally.   The bio on the dust jacket says Brown is an associate professor of magazine journalism at Syracuse University.   Does she meet with the faculty of other disciplines on campus at all?   In my personal experience of 13 years as a student in higher education, ego is not a characteristic lacking in university faculty.   Professors and university researchers are paid to have opinions, and (due to tenure) are given lifetime employment in order to insulate them from the consequences of their opinions.  They’re not often paid terrific amounts of money.  The key features of their jobs are the ability to create standing through thorough and reproducible science and their integrity.  Attacks on research can easily be taken personally.   Professors in the same department who work in the same field sometimes don’t talk to each other, if they can help it.   It happens.  It’s the nature of the beast.
  • She seems to expect that science experts live like cloistered religious or as saints.  She berates the scientific establishment for working with industry and taking money for research.   Who else is supposed to advise industry?  How is research supposed to be funded?  Money can have a corrosive influence because profitable solutions are not always the best ones.  Brown’s documentation suggests that the establishment needs to take another approach.  Ships are slow to turn.  Scientific ideas change, sometimes slowly. The first internationally regarded scientist to emigrate from Europe to the United States in the 19th century was an expert in phrenology and scientific racism.   Science does not generally countenance such ideas today.

So what do I think of the book?  It’s  tough read in parts, and though I have weight problems, it opened my eyes to how people with high BMI, especially women, are treated and generally shamed, constantly.  It’s not a book for the faint-hearted.   It’s also not a book with a lot of answers.   That’s not its purpose, and it’s not the state of nutritional science at the moment.   It does represent a good and mostly honest attempt by a non-scientist to understand the science.   The documentation is excellent.

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