by Mark Hyman
They took flawed research and the resulting flawed government recommendations and amassed a $1 trillion food industry that on the surface sounded healthy but was really anything but. They turned low-fat foods into an aspirational goal for most Americans: low-fat cookies, low-fat sweetened yogurt, low-fat salad dressing, and on and on. The biggest problem is that these foods are loaded with sugar. When you remove fat from foods, it tastes like cardboard, which is why they added sugar. This sugar, as you now know, is the main driver of obesity and heart disease, not fat.
Oops.
SUGAR BECOMES THE NEW FAT
In the late 1970s, in concert with Big Ag (the likes of Cargill and Monsanto) and fueled by new agricultural subsidies that promoted massive increases in the production of corn and soy, Big Food poured high-fructose corn syrup and hydrogenated fats into 600,000 industrial processed foods, 80 percent of which contained added sugar. These high-sugar, high-glycemic foods are highly addictive and spike insulin, which in turn leads to fat storage, hunger, a slow metabolism, and the cholesterol profile most linked to heart disease. Insulin is also the main cause of inflammation—now known to be the real driver of heart disease.
Eating low-fat foods became a virtue as we plowed through giant plates of pasta, oversized bagels, and muffins the size of softballs. But we paid a heavy price for demonizing fat and replacing it with sugar and foods that turn to sugar in our bodies. Ever since we went whole hog (or should I say whole bowl of pasta), dutifully following our government’s misguided and harmful advice since the early 1980s and eating the foods the food industry inventively crafted for the low-fat craze, we went from not a single state having an obesity rate over 20 percent to not a single state having an obesity rate under 20 percent, and now with most states having rates over 25 and even 35 percent. And a full 70 percent of American adults and 40 percent of kids are overweight.
In the 1980s, our sugar consumption (including table sugar and high-fructose corn syrup) was 126 pounds per person per year (a lot). Now it is 152 pounds per person per year. Our consumption of flour, which raises blood sugar more than table sugar does, is about 146 pounds per person per year. That’s a combined average of 1 pound of flour and sugar for every person in America every day! There are mountains of processed food products on the market, and nearly all of those products have added sugar. Your morning low-fat yogurt has more sugar than a can of soda, and your Prego tomato sauce has more sugar per serving than two Oreo cookies. This increase in sugar has tracked perfectly with our obesity epidemic.
Before the 1980s there was almost no high-fructose corn syrup in our diet. Now it is the biggest source of calories in our diet, with each American consuming more than 50 pounds a year. High-fructose corn syrup is especially dangerous because, unlike sugar, which is 50:50 glucose and fructose, high-fructose corn syrup may contain up to 75 percent fructose, which drives obesity, diabetes, cancer, fatty liver, and heart disease. While technically it is true that table sugar consumption has gone down because government subsidies make high-fructose corn syrup cheap and trade tariffs to protect American farmers make sugar more expensive, the total load of sweeteners in all forms has increased dramatically in the last 35 years, tracking exactly with our obesity and diabetes epidemic. It is high-fructose consumption that turns on fat production and storage in your liver through a process called lipogenesis.
According to new government surveys from the National Health and Nutrition Examination Survey, our sweetened beverage consumption (soda, sweetened coffees and teas, energy drinks, etc.) accounts for about 20 percent of our calories. That’s bad news because sugar-sweetened beverages are the “foods” that are the number one cause of obesity and type 2 diabetes. One can of soda a day increases a child’s risk of becoming obese by 60 percent. One can of soda a day increases a woman’s risk of type 2 diabetes by 80 percent. Over the last few decades, sugar consumption surged in Mexico, mostly from soda. Today, 1 in 10 children in that country has type 2 diabetes (what used to be called adult-onset diabetes). What’s remarkable is that soda companies still insist that sugar-sweetened beverages can be a part of a healthy diet as long as the total calories are balanced with the right amount of exercise. This flies in the face of mountains of scientific evidence to the contrary.
Sugar is a main cause of heart disease, too. Those with the highest intake of sugar have a 275 percent increased risk of heart attacks, and those with the lowest intake (which is still relatively a lot) have a 30 percent increased risk. If you think that soda is bad for you only if you gain weight from drinking it, think again. Even if you are skinny and drink sodas and never gain a pound, your risk of heart disease still goes up dramatically!
THE REDEMPTION OF FAT
So now you know the whole story of how we came to demonize fat and glorify sugar, and the price we paid. A few zealous scientists convinced the government to change policy, and the food industry followed right in step to fulfill the demand for low-fat foods. They took the fat out but replaced it with sugar and refined carbs. They were joined by policy makers who jumped on board, and a food industry that was all too happy to fill our plates with low-fat, sugar-laden foods.
But that’s not the end of our story—far from it!
The evidence is now moving away from dietary fat as the root cause of both weight gain and heart disease, and shining a bright and damning light where it belongs: on carbs and sugar. The low-fat era is on its last breath. Even government guidelines are starting to change.
The 2015 US Dietary Guidelines have softened their view on reducing fat and have officially removed limits on dietary cholesterol from their advice. Eggs are back. And professional associations are backpedaling. Even the American Heart Association and the American Cardiology Association have abandoned the low-fat message and have told us to forget completely about worrying about dietary cholesterol.40 Still they focus on saturated fat, but many scientists are questioning the purported dangers of saturated fat.41
Slowly, cautiously, the tide is turning to a more balanced view of what’s good and what’s not. In Part III we will dig into what we should eat, based on today’s understanding. Eat Fat, Get Thin wades through all the confusing research and clears the muddied waters. You will learn which fats (and foods) promote health, help with effortless weight loss, prevent heart disease and cancer, improve your mood and brain function, and help prevent and even reverse dementia in its early stages.42 And all this while eating delicious, deeply satisfying food, because the thing that makes food the most satisfying is fat!
As I’ve said, I myself was confused for a long time about fat, but after reading more than 1,000 scientific papers and seeing more than 20,000 patients, I have a much better sense of the good, the bad, and the ugly fats. I will help guide you to understand the world of dietary fat so that you can make the right choices.
PART II
SEPARATING FAT FROM FICTION
There is nothing more difficult to carry out, nor more doubtful of success, nor more dangerous to handle, than to initiate a new order of things. For the reformer has enemies in all those who profit by the old order, and only lukewarm defenders in all those who would profit by the new order.
—Niccolò Machiavelli, The Prince and The Discourses
3
Eating Fat Does Not Make You Fat!
If you believe that all calories are created equal (and you now know they definitively are not), then it stands to reason that you’d also be quick to demonize fat and blame it for weight gain. It seems like simple math: If fat has more than twice as many calories per gram as carbs or protein, then if you eat less fat, you will eat fewer calories and lose weight. Sounds reasonable, doesn’t it? Unfortunately it just doesn’t work out that way for many reasons.
That all calories are the same in terms of effects on your weight and metabolism is one of the most persistent myths in medicine today. They are the same in a laboratory, when you burn them in a vacuum. But not when you eat them. New public policies require restaurants to list the c
alorie content of each dish, and food companies to label calories per serving in large, bold type. But this is the wrong strategy, because it implies that only calories matter. The truth is that different calories affect your gene expression, hormones, brain chemistry, immune system, metabolism, and even your gut flora differently. While it is helpful to track calories in processed and fast food (because they can be so loaded with bad calories)—it can deter you from eating that 1,200-calorie meal—if you eat real food, you don’t need to track calories.
Metabolism is not a math problem. It’s not about balancing “energy” or calories in and calories out. If it were, and you ate an additional 100 calories a day, which is about a big bite of food, after a year you would gain ten pounds. After a decade you would gain one hundred pounds. This just doesn’t happen. Even if you were the world record holder in calorie counting, you couldn’t get the math right to control your weight.
That’s why weight and metabolism are not math problems. The quality of the food you eat matters much more than the quantity. If food were only about calories, it wouldn’t matter what specific foods you ate, as long as you kept below a certain number of calories. But it does. Why?
Food is not just a source of energy or calories. Food is information. It contains instructions that affect every biological function of your body. It is the stuff that controls everything. Food affects the expression of your genes (determining which ones get triggered to cause or prevent disease) and influences your hormones, brain chemistry, immune system, gut flora, and metabolism at every level. It works fast, in real time with every bite. This is the groundbreaking science of nutrigenomics.
The whole idea that a calorie is a calorie is finally being intensely studied by the Nutrition Science Initiative,1 headed by Dr. Peter Attia and Gary Taubes (author of Good Calories, Bad Calories). The institute is funding rigorous and larger studies by the world’s best researchers to answer this question once and for all and quiet the naysayers—of which there are still many, despite adequate evidence. They are even enlisting scientists who disagree with their hypothesis that all calories are not equal so those scientists can prove themselves wrong.
This is not a new idea. Nutrition expert Ann Louise Gittleman, PhD, CNS, the former director of nutrition at the renowned low-fat, high-carb Pritikin Longevity Center, was the first in the country to write about the importance of fats in her bestselling Beyond Pritikin, released in 1988. For years, she has been a pioneer and the lone voice in promoting the importance of the right fats. She identified the flaws in the science back then and, in thirty of her books that followed, implored us to eat more fat. Sadly, we ignored her prescient advice.
More and more scientists are confirming that calories coming from fat are better for weight loss and improving metabolism. Kevin Hall, from the National Institutes of Health, has found that in a metabolic ward where every ounce of food and every movement and every calorie burned are carefully measured, those who ate more fat calories (compared to an identical number of calories from carbs) burned more than 100 additional calories a day. Over a year that amounts to a ten-pound weight loss. He also reported that in studies of brain imaging and function, eating more fat shuts off the hunger and craving centers of the brain.2 It seems that the brain matters most in terms of controlling food intake, taste preferences, and metabolism. And that dietary fat can positively impact the whole calorie-burning process.
WHY WE OVEREAT
Most of us assume that overeating makes us gain weight. That sounds like a reasonable assumption, right? But in a brilliant paper in the Journal of the American Medical Association, Harvard professor Dr. David Ludwig lays out the case for a very different view of obesity and metabolism.
He says, simply, that we have it backwards. It is not eating more and exercising less that makes you fat, but being fat that makes you eat more and exercise less. Essentially your fat cells “get hungry” and drive you to overeat. He describes this process in detail in his book Always Hungry? When you are overweight, your hormones and brain chemistry make you hungry and tired.3
This turns all our thinking about weight gain upside down and contradicts every single established recommendation for weight loss. Rather than focus on calories and quantity, Dr. Ludwig suggests we focus on quality and the composition of our diet (amount and type of protein, fat, and carbs) to allow the body’s natural intelligence to regulate hunger, activity, metabolism, and weight. Forget about willpower—use science to cut your hunger, give you energy, and speed up your metabolism!
Here’s how this plays out in your biology.
First, when you try to restrict calories and exercise more, your body is hardwired to perceive a starvation situation. That makes you tired (so you move less and conserve energy) and hungry (so you eat more), and it slows down your metabolism (so you don’t die!). This “eat less, exercise more” formula is not too successful for most people. It can work for a short time, certainly, but less than 10 percent of people lose weight and keep it off for a year;4 you will almost always rebound and gain back the weight.
Second, when you eat carbs and sugar, insulin spikes and your blood sugar drops. The insulin drives most of the available fuel in your bloodstream into fat cells, especially the fat cells around your middle, otherwise known as belly fat. So your body is starved of fuel, and this stimulates your brain5 to make you eat more.6 You could have a year’s worth of stored energy in your fat tissue and yet feel like you are starving.
The only thing that can stop this vicious cycle is eating a lot of fat and cutting out the refined carbs and sugar. A high-fat, low-carb diet leads to a faster metabolism and sustained weight loss.
WHY WE GAIN OR LOSE WEIGHT: THE BIOLOGY OF FAT CELLS
What makes our fat cells store fat? What makes them release and burn fat?
We are still learning how our bodies regulate our weight. At the heart of Functional Medicine is the concept of biochemical and genetic individuality. This concept is especially relevant in the world of body weight. There is not just one cause of weight gain. There is a wide range in how we respond to different foods—fats or carbs or protein. Even though we don’t yet have all the answers, we do have enough “dots” to connect and can create the basic recommendations that will work for most of us.
Fat cells are known as adipocytes. Those plump little cells are not just there holding up your pants. They are busy producing all sorts of molecules that control nearly everything related to your weight, and they can drive pathways that promote heart disease, cancer, and dementia.
Hard as it is to imagine, your fats cells are actually endocrine cells that produce many hormones, just like your thyroid or ovaries or testes. Fat tissue is also part of your immune system because it contains white blood cells (macrophages), and the fat cells produce inflammatory messenger chemicals called adipocytokines. Your fat is also influenced by and regulates neurotransmitters—your brain messenger chemicals. It is a storage organ, providing a reservoir of energy when supplies get low (from starvation or low blood sugar). Your fat cells can even produce more fat from carbohydrates in your diet. The active little globules of fat are constantly communicating with your whole body—including your stomach, pancreas, brain, hormones, liver, and more. This complex web of interactions and feedback mechanisms can easily get disrupted.
But the most important thing I can tell you—the final dot in our connect-the-dots story that completes the picture—is that most of the biology of fat cells is controlled by the quality and type of food you eat. And this is why a high-fat, low-carb (low-glycemic), high-fiber, whole-foods diet—like the Eat Fat, Get Thin Plan—works for so many people. Almost everyone will benefit from trying this approach for twenty-one days, especially if you have diabesity. It is a perfect way to reset. Then, after you’ve completed the twenty-one-day program, you’ll enter the transition stage, which you’ll learn about in Chapter 14. During the transition stage, you can see how many metabolic degrees of freedom you have, and you may decide to include a few mor
e healthy carbs, such as whole grains, starchy veggies, and beans, in your diet, all within the healthy eating parameters you’ll learn throughout the program.
HIGH-FAT VS. LOW-FAT DIETS
There has been a lot of research done and much written about low-carb, high-fat diets for weight loss. And the conclusions seem clear: high-fat, low-carb diets work better than low-fat, high-carb diets. Let’s review a few of the important studies that compare low-fat to high-fat diets so you can see exactly how and why I came to that conclusion.
I mentioned the A TO Z Weight Loss Study, published in the Journal of the American Medical Association in 2007,7 in Chapter 2. It was a twelve-month study of 311 overweight, nondiabetic, postmenopausal women. Hands down, the high-fat group in this study did better in every way. They lost twice as much weight, and every cardiovascular risk factor improved. The cholesterol profile shifted from bad to good, with lower triglycerides, higher HDL, and lower total cholesterol to HDL ratio (the best predictor of heart attacks). LDL, or the bad cholesterol, went up a bit, but it shifted from small, dense, dangerous particles to light, fluffy particles—in other words, the total level was higher, but the type was not the kind that causes heart attacks. Blood pressure, insulin and insulin resistance, and blood sugar were all better on the high-fat diet.
Another important study, the DIRECT trial, published in the New England Journal of Medicine in 2008,8 looked at 322 moderately obese people and gave each group a calorie-restricted low-fat diet, a Mediterranean diet, a calorie-restricted diet, or a low-carb, high-fat calorie-unrestricted diet. Guess what? The group that was told to not worry about calories and to eat the most fat lost more than 66 percent more weight. Even more surprising, the ratio of total cholesterol to HDL dropped 20 percent in the high-fat group but only 12 percent in the low-fat group. The high-fat group also had better results by a big margin for HDL, triglycerides, insulin and glucose, and inflammation, and even improvements in fatty liver.