Tuesday, January 08, 2013

the essential Gary Taubes (Why We Get Fat)

In 2010, science writer Gary Taubes published his Why We Get Fat, a book whose aim was to describe human adiposity. My buddy Mike got me this book for my birthday; although he insists there was no hidden message behind the purchase, I don't believe him. Message or not, the book made for an interesting read, and what I'd like to do now is put a crimp on Mr. Taubes's sales by distilling the essence of the author's message in a few brief paragraphs.

The first phase of Taubes's book is about the discrepancy between the scientific evidence regarding adiposity and the prevalent "scientific" wisdom that claims we need to expend more calories than we take in in order to lose weight. Taubes is at great pains to deconstruct the "calories in/calories out" paradigm. He argues that the body reacts to a reduction in caloric intake by becoming increasingly inactive, and that it reacts to an increase in activity by radically increasing appetite. These factors throw off any straightforward "calories in/calories out" calculations.

Next, Taubes argues that adiposity is, in many respects, beyond our control. Here, he uses the analogy of body hair: for genetic and hormonal reasons, some people are naturally hairier than others, and the distribution of their body hair, like their general hairiness, is not a matter of choice. By the same token, the distribution of fat on a person's body, as well as that person's susceptibility to obesity, is beyond that person's control. Taubes's point is that it's unfair when thin people accuse fat people of lacking self-discipline or moral fiber.

Taubes devotes a great deal of space to a study and critique of the history of adiposity science: even as far back as the 1700s, the scientific intuition that carbohydrates were the culprit when it came to fatness was prevalent. It was only in more recent times, especially in the mid to late twentieth century, that the science went off the rails and began to promote a low-fat, high-carb, calories in/calories out paradigm.

Why We Get Fat offers the following chain of causation, which stands at the root of the obesity problem: fat is regulated by insulin production; insulin production depends on blood-sugar levels; blood sugar depends on carbohydrate intake. So: eat carbs, raise blood sugar, produce insulin, get fat. Obviously, I'm doing Taubes an injustice by simplifying his paradigm to this cartoonish extent, but that's essentially what he's arguing, and he claims the science on this is solid. So to the extent that we can control our fat production, the key is a draconian reduction in carbohydrate intake. Once the body undergoes ketosis, which is effectively the metabolizing of its own fat stores for energy, it frees itself from the shackles of carbs-as-energy-source and begins actively to reduce its percentage of adipose. Other salubrious effects include lowering of blood pressure and-- obviously-- blood sugar, which steers one away from diabetes, heart disease, and other cognate problems.

Taubes also takes the time to respond to charges that a diet heavy on meat, fat, and leafy greens is somehow bad for the heart-- a common accusation made against the Atkins Diet, for example. There is no connection, says Taubes, between dietary fat and heart disease. His argument is based on both evidence and evolution:

This idea [that fat intake causes heart disease] is simplistic almost beyond belief. Imagine: hundreds of millions of years of evolution leading to organisms that determine how much fuel and essential nutrients they consume based only on the weight or energy density of the food, or the volume of the stomach cavity in which that food is digested. Not only is it hard to believe, but the experimental evidence has always refuted it. Even by the 1960s, high-fat, carbohydrate-restricted diets had been repeatedly shown to make people lose weight, not gain it. Still, by the 1970s, dietary fat had become the official dietary villain... (p.180)

Taubes uses a rather surprising and convincing image to make his case: note that, in the wild, most predators are lean while most herbivores are fat. (It may be that Taubes's analogy holds water as long as we don't consider bears, which are Nature's fatass predators. But aside from bears, it's hard to name any fat predators, and now that I think of it, bears themselves are actually carbohydrate-consuming omnivores, not exclusively carnivores, so Taubes's imagery remains beyond reproach.)

Essentially, Taubes is siding with Dr. Atkins. He insists the science behind the low-carb, high-protein diet is sound, and he makes a strong case for pursuing such a diet. I'm not as convinced by Taubes's early attempt at refuting the "calories in/calories out" paradigm: by noting that the body reacts to changes in diet and exercise levels, Taubes doesn't successfully make the case that calorie input/output isn't relevant to obesity. He's on much firmer ground, I think, when he argues from the standpoint of evolution and hormonal regulation of adiposity. That chain of causation is clearly explained in Why We Get Fat, and while Taubes's own science background isn't biology (it's actually applied physics and aerospace engineering), I don't want to commit the genetic fallacy and dismiss all of his research merely because of who he isn't.

All in all, I thought Why We Get Fat was a good read. Despite what I joked earlier about trying to put a crimp in Taubes's book sales, I think you should buy the man's book and read his argument for yourself; don't draw any facile conclusions based on this breezy blog post. He knows his way around scientific terminology, and as a dedicated journalist, he's done his homework so that you won't have to. If you're a Buddhist and/or an ethical vegetarian, you're going to be sorely disappointed by Taubes's unapologetic advocacy of the carnivorous lifestyle. The man has nothing against a hearty bacon-and-eggs breakfast.

Just avoid the pancakes and maple syrup.



Elisson said...

Based on my own experience, I would say that a lower-carb (not no carb, which puts you in a more-or-less permanent state of ketosis) diet with carbs and protein in roughly equal quantities works best for me.

Protein moderates the impact of carbs on insulin levels and helps keep the feeling of satiety last longer... which in turn leads to lower calorie consumption.

Also: lotsa green vegetables!

Americans eat way too many refined carbs - starches and sugars - along with the insidious, evil high fructose corn syrup, present in almostr every processed food. Feh. No wonder we have devolved into a nation of grotesqueries...

The Maximum Leader said...

I must first comment and note that, in my own defense, the book was on your wish list (as I recall). And there is no secret meaning behind me getting it for you. (Indeed, I own the book myself.)

In addition to the processed starches I know a huge source of sugar calories for me come from liquor. (And for many Americans - soda.)

Though I've not finished Taubes's book, I often harken back to a few rather lengthy interviews I've read/heard/watched him give. (One particularly good interview was podcasted by Skeptic Magazine, you might find it online.) In one interview he mentioned fruit as a major source of sugar in "healthy" diets. He then gave an exposition on how we've bred fruits to be larger, juicier and more sugary over time. So our prehistoric ancestors might have eaten apples from time to time, but their apples were small, tart and didn't have nearly the sugar ours do today...

He is making a fascinating argument. The most interesting part of the argument to me is his examination of the monolithic thinking among scientists who's field of research is our diet. They seem very reluctant to look at existing evidence differently or even test out some underlying assumptions of their field.

John said...

I've owned this book for over a year now and I haven't lost any weight whatsoever. Based on your review, I'm going to try actually reading it and see if that makes any difference.

Seriously though, the only time I have succeeded at losing weight was on a low-carb Atkins-like diet. I didn't keep the weight off because I do love my bread, cereal, potatoes, and sweets. And of course, beer.

So although I know I need to shed pounds to stay healthy and live longer that voice in my head keeps saying "what's the point if you can't enjoy the things that make life so wonderful?"

Kevin Kim said...


Believe me, I feel your pain. I tried Atkins for about two weeks, and found myself becoming thoroughly depressed as I thought and thought about all the food I was missing out on. I think that, for carb-loving gents like you and me, the only way to tough it out is through the constant encouragement of our fellows. We may need to join a group of some sort so that we're held accountable for our progress, and so that we get the emotional support we'll need to brunt our way through the diet.