Tuesday, August 18, 2015

Fat Chance by Dr. Robert Lustig, M.D.



Few topics are as fraught with controversy as diet. Everyone has one (whether recognized as such or
not), and most everyone has a high degree of confidence that their chosen diet is The Right One. However, most everyone knows that we’re suffering from a pandemic of obesity that continues to grow (literally) and that threatens to shorten life expectancy in the next generation. If you don’t trust statistics about this burgeoning problem, then fly around the world and see for yourself. At airports, it’s easy to spot people likely to be Americans: we’re No. 1—in waist girth and fat fannies. And to make matters worse, the rest of the world is catching up quickly. While most Indians and Chinese remain slender, the younger and wealthier among them are getting bigger and puffier, including more and more kids.

So what do we do about it? We can safely say that we don’t lack for advice. Diet and health books and articles abound. And they all seem to contradict one another. From vegan to Primal/Paleo, from low-fat to low-carb, from Pritikin to Ornish to Atkins we’ve been told, “This is the true path”. We’ve seen villains come and go: fat, salt, meat, carbs—just about everything edible will either kills us or save us. (Which is probably true, but that’s diving to a really deep level.) So what’s a person to do? Keep inquiring.

I’ve been reading books of fitness and nutrition for a long time. I’ve always been interested in how the human body works, how to improve performance, and I aspire to die young when I’m old. Thus, I’ve tried diet experiments of all sorts, including a stint as a vegetarian and fasting. The vegetarian thing was too boring to continue (I love a good steak), but occasional fasting remains a part of my repertoire, albeit not used enough. I’ve read John Robbins of Healthy at 100 (vegan-ish), Colin Campbell of The China Study (meat is the culprit), and Pritikin and Ornish pieces (very low fat—fat bad). I’ve also read in the Paleo/Primal world of Art De Vany and Mark Sisson (among others), and I’ve read Gary Taubes (Good Calories, Bad Calories), who comes down close to the Paleo/Primal perspective. (Taubes's perspective comes mostly from scientific studies for the last two centuries and anthropologic data more than from an evolutionary viewpoint.) I’ve also learned from bio-hacker Dave Asprey (The Bulletproof Diet) and Dr. Peter Atilla, an N=1 student of a ketogenic diet.

I don’t follow any one lead strictly, although the Paleo/Primal, and lower-carb perspectives guide my current train of thought and practice (with some grains and some dairy—who’s perfect?). And I live in China, home of rice and of wheat noodles. Yet, for some reason, I couldn’t resist reading Lustig’s book, although I feared it would only add to my uncertainty and create a risk of dietary nihilism. 

I’m happy to report that I’m glad I read the book and that as a result, I’ve altered my diet. 

Dr. Lustig. Note the cup.
Some may recognize Lustig’s name for his viral YouTube video, "Sugar: The Bitter Truth". (Viral by health and diet standards, anyway. We’re talking 5,856,147 viewings; we’re not talking “Gangnam Style” (239,582,696 viewings) or “What Does the Fox Say?” (537,697,900 viewings) —priorities, right?) Or perhaps you’ve seen or heard about his “60 Minutes” interview. But now he’s written a book, and it’s the most comprehensive look at the obesity epidemic that I’ve seen or could imagine.  

Let me warn you if you’re going to read this book: it covers everything from biochemistry to public policy—and rightly so, because it’s all a part of the understanding the challenge of rampant obesity. So brush off your Krebs cycle cobwebs and put on your political scientist hat to read this. Just kidding! Don’t panic. Dr. Lustig, aiming at a general audience, doesn’t presume you know the process of the Krebs cycle or that you have your degree in biochemistry. He explains it all very well for the lay person. Ditto with the public policy. It’s a matter of clear conceptual thinking and understanding the incentives, and he does just as well in this field as he does with the biochemistry and endocrinology.

In making the rounds with Dr. Lustig, the first thing that you learn is that a calorie is not just a calorie, something that I’d learned earlier from Gary Taubes’s brilliant Good Calories, Bad Calories. A gram of protein, of fat, or of carbohydrate is not just a measure of energy (calorie), but a complex chemical that serves as a signal to the body. In other words, the body responds differently to fats than to proteins than to carbs. Put simply, based on evolution and the uncertain and often sparse food environment in which humans evolved, we developed the capability to store sugars (as in fruit) as fat when it exceeded our immediate energy needs. Insulin, which regulates sugars, prompts the body to store excess sugars as fat. Essential for survival in the wild. A killer in the convenience store. 

The other key biochemical and physiological fact is that fructose (the sweetness in any sugar) is a potential problem. It’s found in any fruit off the vine or tree, honey, processed cane sugar (table sugar), high-fructose corn syrup, and every other natural sweetener. As Dr. Lustig writes: “Finally, we come to the Voldemort of the dietary hit list: the sweet molecule in sugar. If it’s sweet, and it’s caloric, it’s fructose.” Lustig, Robert H. (2012-12-27). Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease (p. 100). Penguin Publishing Group. Kindle Edition. And what’s so bad about fructose? When we consume fructose, especially in large quantities as we are wont to do today, and it isn’t needed right away for energy, it's stored as fat (via insulin, the fat-storage hormone). The more sugar we eat, the more fat we create. (Starches, glucose without fructose, do something similar, but as Lustig puts it, starches will make you fat, but they won’t make you sick.) 

Here’s where a difficult problem that has long perplexed me (and I imagine others) becomes resolved. As I mentioned above, there are all sorts of diets, including some that have survived the test of time (i.e., not just fads) that seem to contract one another, but they have one common trait. Lustig decodes the dietary Rosetta Stone: 

Can low-fat and low-carb diets both be right? Or both wrong? What do the Atkins diet (protein and fat), the Ornish diet (vegetables and whole grains), and the traditional Japanese diet (carbohydrate and protein) have in common? On the surface they seem to be diametrically opposite. But they all have one thing in common: they restrict sugar. Every successful diet in history restricts sugar. Sugar is, bar none, the most successful food additive known to man. When the food industry adds it for “palatability,” we buy more. And because it’s cheap, some version of sugar appears in virtually every processed foodstuff now manufactured in the world. Sugar, and specifically fructose, is the Lex Luthor of this story.
Id. 117-118

By the way, if you thinking “Oh, damn! No fruit?” you’re like me. But Lustig points out that fruit—real fruit—always comes with fiber. And fiber prevents all that fructose from flooding into the body. But beware! Orange juice and other fruit drinks—even 100% fruit—along with “juiced” fruits that destroy the fiber, can provide a fructose jolt even greater than a can of Coke. 

There’s much, much more about the physiology of food and the biochemistry of obesity and its evil off-spring, metabolic syndrome, but I want to skip over that here to share another aspect of the book that proved compelling. 

Lustig emphasizes that obesity is not a matter of sloth and gluttony, as we’re often inclined to think. Lustig notes that we have a number of seats at what he terms “the table of blame” for obesity, with different “guests” having different degrees of culpability. While gluttony and sloth are usually seated at the head of the table commensurate with our individualistic culture and cult of “personal responsibility”, seats are also provided for:
  • the health insurance industry (“obesity is not a disease”); 
  • the medical profession (simple: eat less and exercise more);
  •  the “obesity profiteers” (selling diet books and plans); 
  • “fat activists” (it’s okay to be fat, “make bigger seats”); 
  • the commercial food industry (more food, more profits); and
  •  the federal government (keep crop prices high to please farmers; recommend a diet with lots of cheap carbs). 

Quite a list of suspects.  And all guilty in some measure, but not in the order that you may think. 

Lustig discounts sloth and gluttony as factors. This seems based on the fact that he’s a pediatrician and he can’t see blaming kids for their obesity. In fact, some obesity is the result of purely physiological defects in the body, such as a congenital lack of a hormone. But whatever the source, Lustig emphasizes that hormones drive behavior. And our outside environment shapes our hormonal environment (inside our body). “Biochemistry and hormones drive our behavior”. Id. 34. (If you doubt this, please consider a near-by teenager.) Lustig then expands our horizon: “The obesity pandemic is due to our altered biochemistry, which is a result of our altered environment.” Id. 30.

In the second part of the book especially, Lustig comes to grip with the fact that the worldwide obesity pandemic is a public health problem that screams for public policy remedies, but these remedies encounter the reality of political economics. Lustig discards the still-reigning paradigm of the rational, freely choosing individual as the model of decision-making. As Lustig notes, have you ever met a rational addict? Instead, he focuses on the larger environment of the political economy. (His insights reinforce my maxim that all economics is really political economy; that is, all decisions arise from within a framework shaped by political decisions and social habits created outside of market mechanisms.) Think about it: farmers are paid to grow corn and beans to supply all kinds of processed food (especially after the advent of high-fructose corn syrup). Food companies don’t make money selling raw fruits and veggies. They sell convenient, “tasty”, “low-fat” (extra sugar) foods at almost every street corner (including where we live in China). How do we continually say “no” in this environment? One can (I’m on it now), but it takes energy to say “no” to constant temptation. It’s the way of contemporary consumer capitalism. Lustig identifies the political and economic pressures that make eating healthy (i.e., real food) so challenging. He acknowledges that poor neighborhoods often only have access to a “convenience store” and a McDonald’s. When a mom arrives home late from work and the kids are hungry and cranky, what’s she going to do? Lustig sorts all of these issues out very well, and he isn’t afraid to mark sacred cows for extermination, although he’s enough of a realist to know that change will only come slowly. 

The depth and breadth of this book is truly amazing. It’s written by someone who writes as a scientist for non-scientists, combing the two registers with ease. For your own well-being and that of your loved ones, as well as to satisfy your scientific curiosity, I can’t recommend this book highly enough. 

And I have to admit—with some shame—that I’m glad that I read this book after our trip to Italy and all that delicious gelato. I’m on the sugar wagon now, but—Oh!—what a sweet farewell!

P.S. If you don't have time now to read the book, you might read "Is Sugar Toxic" by Gary Taubes. The article opens with a consideration of Lustig's work. 

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