Read an Excerpt
chapter
1
What “Zero Sugar” Really Means
Let’s talk about the sweet science.
The word probably brings up a lot of mixed feelings. On one hand, hey, sugar! Sweets and treats conjure happy feelings of childhood, summer ice cream, autumn Halloweens, holiday hot chocolates. On the other hand, ugh, sugar! High-calorie junk bombs in colorful wrappers, binge guilt, and all those extra pounds. Not to mention everything you’ve heard about sugar over the years: Too much is poison running through your bloodstream. It’s literally making you sick.
I’m sorry the news isn’t better.
So let’s talk about sugar.
The problem isn’t sugar itself. The problem is we’re consuming too much and we’re not even aware of it. A healthy amount of carbohydrate consumption allows our body systems—particularly our brains, which run on glucose—to operate normally. In today’s world of convenience foods and large serving sizes, it’s difficult to avoid eating too much sugar. Why? Because of “added sugar,” which isn’t just a made-up term describing you dumping a spoonful in a cup of coffee. It’s also not the sugar we consume naturally from eating whole foods. Added sugars are also called “free sugars,” the stuff that doesn’t have a fiber (or protein) accompaniment and is engineered into our food in the manufacturing process.
So lactose, the sugar naturally found in milk and dairy products, and naturally occurring fructose, the sugar that appears in fruit, don’t count. But ingredients that are used in foods to provide added sweetness and calories, from the much-maligned high-fructose corn syrup to healthier-sounding ones like agave, date syrup, cane sugar, and honey, are all considered added sugars.
The formula is simple: If you eat a serving (or more) of a food containing added sugar, you have zero control over how much sugar you’re eating. After all, once the sugar’s added, you can’t move it to the side of your plate or skim it off the top of your drink. It’s in there. And then it’s in you.
So . . . how much added sugar is too much?
The U.S. Department of Agriculture, the World Health Organization, and the American Heart Association have all spoken out against added sugar: The AHA recommends no more than 100 calories per day from added sugars, or six teaspoons, for women, and 150 calories (nine teaspoons) for men. And those recommendations make complete sense: New research suggests that for every 5 percent of total calories you consume from added sweeteners, your risk of diabetes increases by 18 percent. That’s scary because it doesn’t take much added sugar to put yourself at risk. For the average woman, who consumes about 1,858 calories a day, all you need to eat is 93 calories a day of added sugar to significantly boost your risk. There are 4 calories in a gram of sugar, so that means about 23 grams of added sugar per day will put you directly in the path of an oncoming diabetes train.
How easy is it to consume more than 23 grams of added sugar? Consider these common foods people believe are “healthier” options:
• Dannon Fruit on the Bottom Cherry Yogurt: 24 grams • Quaker Natural Granola Oats & Honey: 26 grams • PowerBar Performance Energy Vanilla Crisp: 26 grams • Tazo Organic Iced Green Tea: 30 grams • Ocean Spray Cran-Apple: 31 grams
No one will confuse any of these foods with Snickers bars or a can of Coke. And now you see why trying to avoid added sugars is such a battle. But have no fear. You can—and will—win. Keep reading.
Why Added Sugars Are So Dangerous
Here’s something to think about:
When a doctor suspects a patient to be insulin resistant or possibly diabetic, one way to find out how that patient’s body processes sugar is by prescribing an Oral Glucose Tolerance Test (OGTT). It’s simple: The patient drinks a sugary glucose concoction and the doctor measures her blood glucose at intervals before and after. Sugar hits your bloodstream hard and fast, so it’s easy for the doctor to see how the patient is handling the sugar load. Think of it as a stress test for your pancreas.
Now, consider this: The drink in the OGTT contains 75 grams of sugar. A regular 20-ounce bottle of Coke contains 65 grams of sugar. A 20-ounce Pepsi has 69 grams. A 20-ounce Mountain Dew has 77 grams. You see where I’m headed? Drink a 20-ounce soda and you’re performing the equivalent of a pancreatic stress test on your body—something that’s only supposed to be medically prescribed.
Crazy, right? And illuminating. Let’s take a closer look at the Sugar vs. Your Body smackdown.
Over the centuries, humans got better and better at manufacturing food, and started creating products that dosed us with more rapid-fire sugar than our bodies were designed to handle. With all this blood sugar rushing through your system, the pancreas can sometimes overreact, releasing too much insulin and sucking too much sugar out of our blood. That’s called hypoglycemia, essentially a sugar crash: that shaky, famished feeling that’s different from your standard belly-rumbling hunger.
Because our bodies overreacted and stored all that sugar as fat, we suddenly needed more sugar, and we needed it fast. So sugar rushes cause us to gain weight in two ways. First, because sugar is corrosive to tissues if it lingers in the bloodstream, we store it quickly, often in the form of fat. Second, sugar rushes trigger rebound hunger, causing us to go out and find more sugar, and starting the process all over again.
Almost every health fear you’ve ever stayed up at night worrying about can be linked to this vicious cycle. In a study in The American Journal of Clinical Nutrition, researchers looked at thirty-seven different studies on the effects of high-sugar, low-fiber diets and concluded that “higher postprandial glycemia is a universal mechanism for disease progression.” In English, that means that “meals that raise your blood sugar will kill you.” And not just in one way. If you’re susceptible to heart disease, elevated blood sugar will raise your cholesterol levels and your blood pressure. If diabetes runs in your family, it will boost your chances of developing insulin resistance. If obesity is a risk for you, this is the gateway. In fact, this review found links between high-sugar, low-fiber meals and type 2 diabetes, heart disease, stroke, colorectal cancer, and gallbladder disease.
Not so good, is it? And remember, if you’re regularly consuming foods with added sugar, you’ve given up control of how much sugar you consume. I can’t stress that enough. If the sugar is in there and you eat it, there is no escape. The process has begun.
But wait, there’s more. Here are some other rather important things sugar helps destroy.
Your diet. The more added sugar that sneaks its way into your diet, the less healthy food you’ll eat the rest of the day, according to a 2015 article in Nutrition Reviews that looked at dozens of studies conducted between 1972 and 2012. The researchers found that a higher intake of added sugar was associated with poorer diet and a lower intake of micronutrients. That’s in part because of how sugary foods retrain our taste buds and mess with our bodily systems. When even tomato sauce is laced with sweetener, we then need greater and greater doses of sugar in order for the flavor to register. That leads us to seek out candies and baked goods at the expense of real food.
Your weight. Within twenty-four hours of eating fructose, your body is flooded with elevated levels of triglycerides. Does that sound bad? It is. Triglycerides are the fatty deposits in your blood. Your liver makes them, because they’re essential for building and repairing the tissues in your body. But when it’s hit with high doses of fructose, the liver responds by pumping out more triglycerides; that’s a signal to your body that it’s time to store some abdominal fat. In one study, researchers fed subjects beverages sweetened with either glucose or fructose. Both gained the same amount of weight over the next eight weeks, but the fructose group gained its weight primarily as belly fat, thanks to the way this type of sugar is processed in the liver. And how about this: People who consumed beverages containing high-fructose corn syrup for two weeks significantly increased their levels of triglycerides and LDL cholesterol (the “bad” cholesterols), plus two proteins associated with elevated cholesterols and another compound, uric acid, that’s associated with diabetes and gout, reported The American Journal of Clinical Nutrition in 2015.
Your energy. There are a lot of ways that added sugar can make you gain weight, but the most bizarre may be the way it reduces actual physical activity. In one study at the University of Illinois, two groups of mice were followed for two and a half months; both groups were fed the same amount of sugar and calories, but one group was fed a diet that mimicked the standard American adolescent’s diet, i.e., one that was about 18 percent added fructose. The other set received its sugar in the form of glucose. The added fructose group gained more body fat over the course of the study, even though they weren’t fed more calories—or even more sugar. One of the reasons was that the fructose-addled mice traveled about 20 percent less in their little cages than the other set of mice. They just . . . slowed . . . down.
Your brain. In one recent study, researchers found that a combination of sugar and fat could actually change one’s brain chemistry. The brains of animals on a high-fat, high-sugar diet had decreased levels of brain-derived neurotrophic factor (BDNF), a compound that helps brain cells communicate with one another, build memories, and learn new things. In another study in the journal Diabetologia, researchers found that when blood glucose levels are elevated, BDNF levels drop. That means that the simple act of eating sugar makes you instantly dumber. Decreased levels of BDNF have also been linked to both Alzheimer’s and depression.
Your mood. In a 2015 study of postmenopausal women, higher levels of added sugars and refined carbs were associated with an increased likelihood of depression, while higher consumption of fiber, dairy, fruit, and vegetables was associated with a lower risk.
Your blood pressure. In fact, sugar may be worse for your blood pressure than salt, according to a paper published in the journal Open Heart. Just a few weeks on a high-sucrose diet can increase both systolic and diastolic blood pressure. Another study found that for every sugar-sweetened beverage, risk of developing hypertension increased 8 percent. Too much sugar leads to higher insulin levels, which in turn activates the sympathetic nervous system and leads to increased blood pressure, according to James J. DiNicolantonio, PharmD, cardiovascular research scientist at Saint Luke’s Mid America Heart Institute in Kansas City, Missouri. The theory: It may also cause sodium to accumulate within the cell, causing calcium to build up within the cell, leading to vasoconstriction and hypertension.
And here’s the thing about added sugar that bothers me the most:
It’s addictive. A study at New York University found that a rise in insulin—resulting from sugar consumption—causes a simultaneous rise in dopamine, a neurotransmitter that triggers the brain’s pleasure center. That’s why sugar feels so good to eat in the moment. All of our brain bells and whistles are going off as sugar takes over our bodies. An editorial in JAMA Internal Medicine asked, “Why Are We Consuming So Much Sugar Despite Knowing Too Much Can Harm Us?” The answer: “The high prevalence of added-sugar consumption . . . is very likely influenced by and a result of addictive behaviors incited by reward system activation after overeating highly palatable foods.”
That’s right. The more you eat, the worse it gets, the more you want.
So . . . Are All Sugars Bad?
That’s a complicated question, but the general answer is no. That answer depends on the quantity consumed, of course, but the simple fact is that not all sugars are created equal.
Sugar comes in pretty much three forms:
Sucrose: That’s table sugar to you and me. It’s the granular stuff in Grandma’s apple pie, the lump or two you add into your coffee, the fine white powder that’s dusted over a deep-fried funnel cake. Sucrose is a slightly complicated molecule, so our bodies don’t really want to have to deal with it. In fact, within seconds of sucrose hitting our intestines, our enzymes split it into two separate molecules: glucose and fructose.
Glucose: A simple sugar found in all carbs, glucose is used immediately by our bodies for energy, or stored in the muscles and the liver as glycogen. Glucose is the stuff that shoots directly into the bloodstream and causes our pancreas to pump out insulin; insulin pulls it out of the bloodstream so the body can use it and, if there’s too much of it, stores the excess as fat.
Fructose: The body can’t really use fructose for energy, at least not right away. Fructose is instead shuttled to the liver, where it’s metabolized and stored as fat. This process causes spikes in the hormone ghrelin, the “I’m still hungry” hormone that sends us out seeking additional calories. Fructose behaves in the body much the way alcohol does, and has the same damaging effect on the liver; the only difference is that you don’t catch a buzz.
Fructose may be the most problematic type of sugar, health-wise: According to one study, fructose may increase blood pressure, increase heart rate, and boost myocardial oxygen demand (basically, how much oxygen your heart needs to function). It may also contribute to inflammation, insulin resistance, and overall metabolic dysfunction. And we get more fructose in our diets today than was ever possible efore, thanks to high-fructose corn syrup, the sweetener used in soda and most other convenience foods.
But wait: Fructose is also the sugar naturally found in fruit. So isn’t it healthy? Not really. It’s almost impossible to eat too much fructose through natural means. Consider this: You’d need to eat six cups of strawberries to get the same amount of fructose as in one can of Coke. That’s in part because high-fructose corn syrup is a type of sugar that simply doesn’t exist in nature. Corn syrup itself is 100 percent glucose, but to make it sweeter, manufacturers add pure fructose until the mix is 55:45 fructose to glucose. That makes for a sweetener that’s unnaturally high in the very form of sugar that has health experts so concerned.
Oh, and even if you did decide to eat six cups of strawberries, you’re still not going to cause the same sort of fructose overload as you will with just one soda. That’s because the fiber in strawberries (and any other fruit) helps to slow down digestion and prevent rapid blood sugar spikes. The Coke, by delivering the same amount of fructose in concentrated liquid form, creates an instant sugar high.
Why the Zero Sugar Diet works so well