Why We Get Fat
And What To Do About It
Why do we get fat? It’s a surprisingly simple question that surprisingly few nutrition experts answer with attention to scientific rigor. Enter: Gary Taubes, a brilliant, award-winning science journalist. In this Note we’ll explore some Big Ideas on the importance of the hormone insulin, why carbs are kinda like cigarettes and the Stanford A TO Z Study that showed low-carb diets outperforming others.
Big Ideas
- Why Do We Get Fat?Hormones not calories.
- Cigarettes & Carbs —>Lung cancer & obesity.
- CarbsNot all are created equal.
- Sugar and FlourThe root of Western disease.
- A TO Z Weight Loss StudyAtkins to Zone. Winner? Atkins.
- Low-Fat DietsWhy do people lose weight?
- Next StepsNot a diet per se.
“In more than six decades since the end of the Second World War, when this question of what causes us to fatten—calories or carbohydrates—has been argued, it has often seemed like a religious issue rather than a scientific one. So many different belief systems enter into the question of what constitutes a healthy diet that the scientific question—why do we get fat?—has gotten lost along the way. It’s been overshadowed by ethical, moral, and sociological considerations that are valid in themselves and certainly worth discussing but have nothing to do with the science itself and arguably no place in the scientific inquiry.”
~ Gary Taubes from Why We Get Fat
Why do we get fat?
It’s a surprisingly simple question that surprisingly few nutrition experts answer with attention to scientific rigor.
Enter: Gary Taubes, a brilliant, award-winning science journalist with a ruthless commitment to drilling past the common myths propagated over the last several decades into the scientific research underpinning what we know about why we get fat. (And, as the sub-title suggests, what we can do about it.)
The short answer: It’s the carbs.
Taubes’s first book on the subject was Good Calories, Bad Calories in which he painstakingly walks us through a comprehensive review of the scientific literature over the last couple hundred years. That book is 600+ pages long—150 of which are Notes and references.
This book is a still rigorous but much quicker-reading look at the issues.
Unless you’re already familiar with his argument, the book will almost certainly challenge your current ideas. If your mind is open, it’s hard to argue with the central theme Taubes presents.
The book is packed with Big Ideas and studies. We’ll barely scratch the surface but I’m excited to share some of my favorite Ideas and I hope I inspire you to dig deeper into what’s driving our society’s (and perhaps your!) challenges with obesity. (You can get the book here!)
Let’s jump in!
Download MP3
Download PDFI’m going to argue that this calories-in/calories-out paradigm of adiposity is nonsensical: that we don’t get fat because we eat too much and move too little, and that we can’t solve the problem or prevent it by consciously doing the opposite.
Get the Book
Listen to the PodcastHormonal Imbalance vs. a caloric one
“In other words, the science itself makes clear that hormones, enzymes, and growth factors regulate our fat tissue, just as they do everything else in the human body, and that we do not get fat because we overeat; we get fat because the carbohydrates in our diet make us fat. The science tells us that obesity is ultimately the result of a hormonal imbalance, not a caloric one—specifically, the stimulation of insulin secretion caused by eating easily digestible, carbohydrate-rich foods: refined carbohydrates, including flour and cereal grains, starchy vegetables such as potatoes, and sugars, like sucrose (table sugar) and high-fructose corn syrup. These carbohydrates literally make us fat, and by driving us to accumulate fat, they make us hungrier and they make us sedentary.”
That’s the essence of the book in a very tiny nutshell.
Most of the world’s leading experts and the institutions declaring why we get fat (and what to do about it) tell us it’s a caloric issue—an imbalance between “calories-in/calories-out” such that we’re consuming more energy than we’re expending.
By their logic, if you’re fat all you need to do is consume less calories than you burn. Super simple! This would be awesome if it were true. Unfortunately, Taubes tells us again and again, it’s not.
We get fat because of a HORMONAL imbalance, not a caloric imbalance.
Taubes walks us through the detailed process of how carbohydrates trigger a release of insulin to remove the excess sugar from our bloodstream and that this process running overtime as a result of an excess consumption of carbs is the primary reason we’re fat.
Cigarettes & Carbs —> lung Cancer & Obesity
“Whether you’re born predisposed to get fat is beyond your control. What Adiposity 101 teaches us, though, is that this predisposition is set off by the carbohydrates we eat—by their quantity and their quality. As I said, it’s carbohydrates that ultimately determines insulin secretion and insulin that drives the accumulation of body fat. Not all of us get fat when we eat carbohydrates, but for those of us who do get fat, the carbohydrates are to blame; the fewer carbohydrates we eat, the leaner we will be.
A comparison with cigarettes is apt. Not every longtime smoker gets lung cancer. Only one in six men will, and one in nine women. But for those who do get lung cancer, cigarette smoke is far and away the most common cause. In a world without cigarettes, lung cancer would be a rare disease, as it once was. In a world without carbohydrate-rich diets, obesity would be a rare condition as well.”
Another factor that influences our predisposition to getting fat (and limits the utility of the calories-in/calories-out paradigm) is our genetics—some people are more likely to get fat than others. I, for example, fall on the lean side and it’s not a big concern.
Having said that, those of us who are predisposed to getting fat, will get fat as a result of the carbs we consume.
As Taubes tells us, it’s kinda like smoking and lung cancer—not *everyone* who smokes will get lung cancer, but if you do get lung cancer, the primary cause is almost certainly smoking.
David Perlmutter references this gem in his great book Grain Brain (see Notes) where he tells us: “The more sugars we eat, the more we tell our bodies to transfer them to fat. This happens not only in the liver, leading to a condition called fatty liver disease, but elsewhere in the body as well. Hello, love handles, muffin tops, beer bellies, and the worst kind of fat of all—invisible visceral fat that hugs our vital organs.
I love how Taubes draws a parallel between the cause-and-effect relationship uniting carbohydrates and obesity, and the link between smoking and cancer: If the world had never invented cigarettes, lung cancer would be a rare disease. Likewise, if we didn’t eat such high- carb diets, obesity would be a rare condition. I’d bet that other related conditions would be uncommon as well, including diabetes, heart disease, dementia, and cancer. And if I had to name the kingpin here in terms of avoiding all manner of disease, I’d say ‘diabetes.’ That is to say, don’t become diabetic.”
Not all carbs are created equal
“Not that all foods that contain carbohydrates are equally fattening. This is a crucial point. The most fattening foods are the ones that have the greatest effect on our blood sugar and insulin levels. These are the concentrated sources of carbohydrates, and particularly those that we can digest quickly: anything made of refined flour (bread, cereals, and pasta), liquid carbohydrates (beers, fruit juices, and sodas), and starches (potatoes, rice, and corn). These foods flood the bloodstream quickly with glucose. Blood sugar shoots up; insulin shoots up. We get fatter. Not surprisingly, these foods have been considered uniquely fattening for nearly two hundred years.”
As a thoroughly conditioned American and former low-fat, high-carb vegan, I still find it somewhat mind-boggling that eating fat isn’t what makes us fat and that, in fact, it’s the CARBS that do the trick.
But, then I remind myself that it’s the way carbs trigger an insulin response that drives the fat storage then I step on the scale to see that my body fat is pretty much always at 9% (~ 1/2 of what it was before I shifted to more fat) even though I eat a TON (!!) of fat and very little carbs. Wacky.
Alas, again, it’s the carbs that make us fat.
And, the worst offenders are the carbs that are most quickly digested—leading to the most significant insulin spike.
Here’s another gem from Perlmutter’s Grain Brain that echoes Taubes point to help drive it home: “When I give lectures to members of the medical community, one of my favorite slides is a photo of four common foods: (1) a slice of whole-wheat bread, (2) a Snickers bar, (3) a tablespoon of pure white sugar, and (4) a banana. I then ask the audience to guess which one produces the greatest surge in blood sugar—or which has the highest glycemic index (GI), a numerical rating that reflects a measure of how quickly blood sugar levels rise after eating a particular type of food. The glycemic index encompasses a scale of 0 to 100, with higher values given to foods that cause the most rapid rise in blood sugar. The reference point is pure glucose, which has a GI of 100.
Nine times out of ten, people pick the wrong food. No, it’s not the sugar (GI = 68), it’s not the candy bar (GI = 55), and it’s not the banana (GI = 54). It’s the whole-wheat bread at a whopping GI of 71, putting it on par with white bread (so much for thinking whole wheat is better than white). We’ve known for more than thirty years that wheat increases blood sugar more than table sugar, but we still somehow think that’s not possible. It seems counterintuitive. But it’s a fact that few foods produce as much of a surge in blood glucose as those made with wheat.”
Nuts.
P.S. The carbs that are best for us? Those found in leafy greens and green veggies. They’re wrapped in fiber and packed with water which make their assimilation much more pleasant.
Sugar and Flour
“Clearly, as Pollan points out, humans can adapt to a wide range of non-Western diets, from those exclusively animal-based to those mostly, if not exclusively, vegetarian. If all of those populations were relatively free from Western diseases, as they apparently were, the more logical question to ask is what is it that distinguishes Western diets from the diet of all these populations, not just some of them (the ones that eat copious vegetables and fruits, for instance, and little meat). The answer, it turns out, is the same foods that were absent entirely among the hunter-gatherer populations (in which Western diseases were also mostly absent): ‘cereal grains, dairy products, beverages, vegetable oils and dressings, and sugar and candy.’
Researchers who studied this evidence in the 1950s and 1960s—Thomas ‘Peter’ Cleave and George Campbell, co-authors of Diabetes, Coronary Thrombosis and the Saccharine Disease (1966), deserve the most credit—made the point that when isolated populations start eating Western foods, sugar and white flour are inevitably first, because these foods could be transported around the world as items of trade without spoiling or being devoured on the way by rodents and insects. The Inuits, for example, living on seals, caribou, and whale meat, begin eating sugar and flour (crackers and bread). Western diseases follow. The agrarian Kikuyu, living in Kenya, start eating sugar and flour, and these diseases appear. The Maasai add sugar and flour to their diet or move into the cities and begin eating these foods, and the diseases appear. Even the vegetarian Hindus in India, to whom the fleshpot was an abomination, ate sugar and flour. Doesn’t it seem a good idea to consider sugar and flour likely causes of these diseases?”
Sugar and flour.
Sugar and flour.
Sugar and flour.
When we look at traditional cultures with relatively little Western diseases, then look at what was first introduced into their diets that preceded the rapid expansion of disease, we see SUGAR and FLOUR—two easily transported foods that wreaked havoc once they arrived.
Why?
They spiked insulin.
Note: Even if you don’t agree with everything in here (or are diametrically opposed), every one agrees that eliminating these two items from your diet is a wise idea. So, if you’re not feeling quite optimal, consider eliminating them from your life and see if you notice some huge benefits!
A to Z Weight Loss Study
“Even though the subjects on the Atkins diet were counseled to eat as much food as they wanted, to eat copious amounts of red meat and thus the saturated fat that goes with it, they lost more weight, their triglycerides dropped further (a good thing), their HDL went up further (a good thing), and their blood pressure down further (a good thing) than those on any of the other diets.
Here’s how the Stanford researchers describe the results:
Many concerns have been expressed that low-carbohydrate weight-loss diets, high in total and saturated fat, will adversely affect blood lipid levels and cardiovascular risk. These concerns have not been substantiated in recent weight-loss diet trials. The recent trials, like the current study, have consistently reported that triglycerides, HDL-C [HDL cholesterol], blood pressure and measures of insulin resistance either were not significantly different or were more favorable for the very-low-carbohydrate groups.
The point man on this trial was Christopher Gardner, director of Nutrition Studies at the Stanford Prevention Research Center. Gardner presented the results of the trial in a lecture that’s now viewable on YouTube—“The Battle of Weight Loss Diets: Is Anyone Winning (at Losing)?” He begins the lecture by acknowledging that he’s been a vegetarian for twenty-five years. He did the study, he explains, because he was concerned that a diet like the Atkins diet, rich in meat and saturated fat, could be dangerous. When he described the triumph of the very low-carbohydrate, meat-rich Atkins diet, he called it ‘a bitter pill to swallow.’”
Well, there ya go.
This Stanford-based research project demonstrated that a very-low-carbohydrate diet is not dangerous. And, in fact, it outperformed all the other diets in the study.
Published in The Journal of the American Medical Association in 2007, the study was known as the “A TO Z Weight Loss Study” as it compared everything from Atkins (A), a traditional diet and the Ornish diet to the Zone Diet (Z).
That’s a remarkably compelling response to the question of whether a very-low-carbohydrate diet is dangerous. Nope. And it actually outperformed others.
(For the record, the diet they studied allowed 20 grams of carbs a day for the first two to three months, then 50 grams, with as much protein and fat as desired.)
Why do people lose weight on low-fat diets?
“The simple answer to the question of why we get fat is that carbohydrates make us so; protein and fat do not. But if this is the case, why do we all know people who have gone on low-fat diets and lost weight? Low-fat diets, after all, are relatively high in carbohydrates, so shouldn’t these fail for all the people who try them?
Most of us know people who say they lost significant weight after joining Weight Watchers or Jenny Craig, after reading Skinny Bitch or French Women Don’t Get Fat, or following the very low-fat diet prescribed by Dean Ornish in Eat More, Weight Less. When researchers test the effectiveness of diets in clinical trials, like the Stanford University A To Z Trial that I’ll discuss shortly, they’ll invariably find that a few subjects do indeed lose considerable weight following low-fat diets. Doesn’t this mean that some of us get fat because we eat carbohydrates and get lean again when we don’t, but for others, avoiding fat is the answer?
The simple answer is probably not. The more likely explanation is that any diet that succeeds does so because the dieter restricts fattening carbohydrates, whether by explicit instruction or not. To put it simply, those who lose fat on a diet do so because of what they are not eating—the fattening carbohydrates—not because of what they are eating.”
So…
Why do some people lose weight on a low-fat, higher-carb diet?
Taubes tells us that the simple answer is that when people go on pretty much ANY diet, the first things they tend to eliminate are the most obviously unhealthy foods—which happen to be the most fattening carbohydrates.
Stuff like caloric sodas—Coca Cola, Pepsi, Dr. Pepper—will be replaced with diet versions or water. Beer will be light or eliminated. No more donuts and candy bars.
Taubes tells us that although people may think what they’re doing is effectively cutting calories, why it really works is that they’re cutting the most fattening carbs: “Even the very low-fat diet made famous by Dean Ornish restricts all refined carbohydrates, including sugar, white rice, and white flour. This alone could explain any benefits that result.”
Fascinating!
P.S. This logic also applies to the question of why populations that eat a ton of rice and other grains can do so without getting diabetes and other Western diseases.
Here’s how Taubes puts it:
“It’s quite possible that if we never ate these sugars we might never become fat or diabetic, even if the bulk of our diet were still starchy carbohydrates and flour. This would explain why some of the world’s poorest populations live on carbohydrate-rich diets and don’t get fat or diabetic, while others aren’t so lucky. The ones that don’t (or at least didn’t), like the Japanese and Chinese, were the ones that traditionally ate very little sugar. Once you do start to fatten, if you want to stop the process and reverse it, these sugars have to be the first to go.”
Next steps
“This is not a diet book, because it’s not a diet we’re discussing. Once you accept the fact that carbohydrates—not overeating or a sedentary life—will make you fat, then the idea of ‘going on a diet’ to lose weight, or what the health experts would call a ‘dietary treatment for obesity,’ no longer holds any real meaning. Now the only subjects worth discussing are how best to avoid the carbohydrates responsible—the refined grains, the starches, and the sugars—and what else we might do to maximize the benefits of our health.”
I love that distinction.
Once we realize that it’s the carbs that make us fat, we don’t need to “go on a diet,” we just need to quit eating the stuff that’s compromising our health. :)
The super simple plan Taubes presents in the Appendix to his book is based on one used at the Lifestyle Medicine Clinic at the Duke University Medical Center (which adapted their directives from the Atkins Center for Complementary Medicine).
Basic idea: “Eat as much as you like of meat, fish, fowl, eggs, and leafy green vegetables. Avoid starches, grains, and sugars and anything made from them (including bread, sweets, juices, sodas), and learn for yourself whether and how much fruit and non-starchy vegetables (such as peas, artichokes, and cucumbers) your body can tolerate.”
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