Own the Day, Own Your Life: Optimised practices for waking, working, learning, eating, training, playing, sleeping and sex. Aubrey Marcus

are complex carbohydrates. This isn’t because starchy carbs have commitment issues; rather it refers to their chemical bonds, which take longer to break down in the body. So carbohydrates like potatoes, rice, or quinoa are just a slower form of sugar, with a few more nutrients on board, than refined carbohydrates like simple sugar (aka candy cocaine), white bread, or that stuff that holds a Pop-Tart together. And slower is always better, since it gives your body a longer and more accurate window of time to respond to the glucose, or glycogen, that all sugars eventually metabolize into for the purpose of providing fuel to every living cell, including the brain.

      A lot of people use sugar’s role as cellular fuel as a reason to say that sugar isn’t so bad after all. But our bodies are smarter than that. If we don’t have sugar in our diet, our body will get all Walter White and produce it. This is why even on an almost pure-fat diet like the ketogenic diet, the brain still has ample glucose to survive, but on a pure sugar diet, we’d turn into anxious, confused, irritable, obese, diabetic messes.

      Remember, when sugar passes from the digestive tract, it enters the bloodstream, and blood sugar rises. Left alone, it becomes toxic, so as a response the body releases insulin, and the liver converts this sugar into fuel in the form of glycogen. But the liver can convert only so much before the glycogen stores become “full,” much as your mobile phone battery can’t store more energy than 100 percent of its capacity. So what does the liver do with the excess sugar? It converts it to fat, of course, which is the body’s secondary fuel storage system.

       Deep Dive—Sugar Metabolism and Insulin Resistance

      When the blood contains moderate amounts of sugar, and the body has ample time between releases of insulin, things work pretty well. However, when there is a constant level of sugar in the blood, or consistent spikes of blood sugar, not only does the liver convert sugar to fat, but the body has to release a commensurate level of insulin to keep up. Naturally, if there is a fast increase in blood glucose, there will be a fast increase in insulin. Often this leads to an overcorrection, as the body is in a hurry to drop blood sugar levels. This rapid increase then causes a swift drop in blood glucose concentrations, resulting in the “crash” we dread so much and, when you have too much often enough, a tolerance to insulin called insulin resistance. When the cells become insulin-resistant, they aren’t able to shuttle the sugar from the blood into the cells as efficiently, and so you aren’t able to remove it from the blood. At a certain point this becomes type 2 diabetes, and the injection of additional insulin becomes necessary to reduce blood sugar.

      But let’s take a second to expand on that cell-phone-battery analogy, just to be crystal clear: The sugar power supply keeps flowing into your phone, representing your body, even after the glycogen battery is full. Since the battery can’t charge anymore, your phone stores the extra energy as a cushiony layer of fuel supply (fat) like a phone case. The longer you keep the sugar power supply flowing without draining the battery (exercising), the larger and wider the cushion around your phone becomes. Then, before you know it, your phone is on a reality show called My Six-Hundred-Pound Phone, and they have to cut a giant hole in the side of your house to get it out. I don’t care how much you want to be famous, that’s not the way to do it.

      To be fair, there is a time and place for carbohydrates, but it isn’t breakfast. We’ll talk more about how to intelligently work carbohydrates and even a little bit of sugar into your diet later in the book. But for now, remember the D.A.R.E. campaign and just say no to the white powder, in all its forms.

      Universal Nutrition Principle #2: Fat Is Your Friend

      In 1980, when saturated fat was rising through the ranks toward public enemy number one, only 15 percent of Americans were obese. Today that number is 36 percent. All across the Western world, instead of improving heart disease and obesity, we’ve doubled and, in some cases, as in the UK, tripled it.

      How did we get here? I don’t have enough fingers to point at all the people, organizations, institutions, and cultural forces responsible, but there was a pivotal moment in the latter third of the twentieth century when two influential men espoused radically different ideas about nutrition, and the wrong guy won. One man, Ancel Keys, vehemently believed that dietary fat caused heart disease, a theory that would eventually be known as the diet-heart hypothesis. The other, a scientist named John Yudkin, quietly understood that it was really sugar—pure, white, and deadly—that led to inflammation and obesity. The world chose Mr. Keys’s diet-heart hypothesis, and now the bloated consequences of that decision have created a public health holocaust: when we decided that dietary fat (and its associated cholesterol) was bad for your health, we started removing fat from our foods and replacing it with sugar and vegetable oils to make up for the flavor we’d lost in the removal process. That two-pronged dietary decision began the pincer movement that landed us in the clutches of the obesity, diabetes, and cardiovascular epidemics we face today.

      Placing blame is beside the point at this juncture, however; what is most important is continuing to do good science—work that, not surprisingly, continues to show just how wrong all those diet-heart guys really were. Work like the gigantic landmark meta-analysis in 2010 that, after a review of data from twenty-one studies that included 347,747 participants, found no evidence that saturated fat increases the risk of heart disease. In case you missed that, let me repeat—no evidence that saturated fat increases heart disease.

      Or the research published in the Journal of the American Medical Association in 2006 that looked at 48,835 women who reduced their total fat intake to 20 percent of calories and increased consumption of fruits, vegetables, and grains in its place. If saturated fat was the problem, then surely replacing it with fruits, vegetables, and grains was the solution, right? Wrong. After more than eight years, the replacement of fat had not lessened the risk of coronary heart disease, stroke, or cardiovascular disease.

      Or the 1998 paper before that, from the Journal of Clinical Epidemiology, that examined people in thirty-five countries around the world, looking for a direct link between dietary fats and cardiovascular disease. The conclusion: “The positive ecological correlations between national intakes of total fat and saturated fatty acids and cardiovascular mortality … were absent or negative.” In other words, people in nations with higher-fat diets were not dying of heart disease.

      But we shouldn’t look at cardiovascular disease as the only endpoint for the science of fat. What was the quality of life of those eating more fats? William Castelli, the director of another study in Framingham, Massachusetts, that started in 1948 and is currently in its third generation of participants, has an answer: “We found that the people who ate the most cholesterol, ate the most saturated fat, ate the most calories, weighed the least and were the most physically active” (emphasis added). This is probably not what you grew up hearing. Nonetheless these findings have been confirmed by the recent resurgence of the ketogenic diet. A meta-analysis of over 1,200 subjects in multiple clinical trials has shown that the high-fat, very low-carb ketogenic diet helps you lose more weight than a low-fat diet.

      To put it another way: if you don’t eat fat, you’re probably fat. This is a hard reality to accept for a lot of people. Because at a surface level it makes sense that something called fat in food would create fat in the body. Fat = fat, right? Wrong. You’ll want a lot more fat in your diet than you think, despite what all those diet-heart haters have had to say about things like saturated fat and its unfairly villainized companion, cholesterol.

       Deep Dive: The Truth about “Good and Bad” Cholesterol

      Cholesterol is a fatlike substance your body uses in its cells and tissues for, among many other things, the production of hormones like testosterone and estrogen, which are essential to maintaining good health and protecting against certain types of cancer and depression. To do that, cholesterol needs help getting transported into the body at the cellular level. It needs a ride, basically. Think of cholesterol as cargo and the cell as the port where it needs to be delivered. The best way to deliver it is by boat, a boat made of lipoproteins, which is what most people are referring to when they measure your cholesterol. This is where the confusion and misinformation around “good” and “bad” cholesterol begins.

      In reality, there is only one