INTRODUCTION

What time is it?

Chances are it took you 0.047 second to answer that question. That’s because you’re never more than a few inches from a timepiece. Clocks in the car and on your phone. Clocks on your computers and on the wall. Clocks on your wrist and in the corner of the TV screen. Clocks on your nightstand and along city blocks.

Tick tock, the world doesn’t stop.

With some exceptions, many of us revolve our entire lives—both work and play—around schedules, appointments, calendars, and the rhythm of minutes, hours, and days. Time is the universal metronome of our lives.

The funny thing is that our bodies work in the same way. They operate with a strong desire to sync what you do with when you do it.

But instead of a grandfather clock on your colon, a pocket watch dangling from your liver, and a smartphone attached to your meniscus, your body works with an internal rhythm that allows it to function optimally for survival.

The collective diet industry has spent a lot of time addressing the “what” part of eating: Fruit is better than fries, nuts are better than chips, and bears may be onto something because salmon may just be the most perfect food in the world. But we have spent little time on, well, time—the “when” part of the equation.

As it turns out, major scientific breakthroughs have begun to prove that when it comes to nutrition, timing is everything. The research is so new that it’s literally changed the way we eat (and we thought we knew everything about food!). As it turns out, when you eat is as essential as what you eat for maintaining a good weight, preventing and curing some diseases, and living a long, energetic, and happy life.

This book is about exploring the intersection between the “what” and the “when.” We’ve pulled together all the latest research so you can learn when to eat for optimal health, to minimize stress, and to deal with just about every situation you may encounter over the course of a day. This information just may change your life—and allow you to be your best self.

Now, we’re not going to be so strict that you have to chow down on blueberries at 10:23 a.m. every day or eat a bowl of spinach at 4:07 p.m. every afternoon. But we are going to explain the science of how your body’s circadian rhythms are programmed to best metabolize and use food for your own benefits—and how you can tap into those rhythms through your eating habits. By the time you’re finished reading, you’ll understand how the “When Way” will help you achieve all of your health goals—whether losing 10 or 50 pounds, helping you decrease your blood pressure, reducing the pain in your knees, or providing the day-to-day energy you need.

We have spent our medical careers working on the integration of food and medicine (albeit in different ways) and share at least one guiding principle: Food matters. A lot. It matters medically, it matters biologically, it matters physically, it matters emotionally, and it matters socially. It matters in every sphere of life.

There is no question that food has an impact on your health; science has proven it over and over again. But the only “magic pill” we believe in is how—and when—you decide to approach every day and every meal.

As you prepare to launch into the guts of the book, we want you to keep a few of our other guiding principles in mind; they serve as background for what we believe about food and how it can work to improve your health. We’ll make references to these principles throughout these pages, but understanding them from the start will help you digest (sorry!) the material a bit more easily:

1. Food Is Medicine. Since the time of Hippocrates, physicians have used the power of food to treat disease.1 Unfortunately, though, our medical system has evolved to alleviate illness, rather than keep you healthy. Instead of developing the tools to prevent disease, we wait for the disease to arrive, and then treat it.

Although we spend more money on health care than any other country in the world, the expected life span in the United States has steadily decreased over the past two years. And we are outlived by people of dozens of other countries.2,3

Health should be about more than just the absence of disease. It should be about living longer, having high energy, experiencing peak performance for a long time, keeping your immune system sharp, avoiding chronic disease, and strengthening your body to fight off problems and the effects of aging.

That power comes from food.

Although many variables play a role in your health (activity, exposure to toxins, genes), the single most important decision you make every day is what you choose to put in your mouth. In fact, what you eat actually influences whether your genes are expressed—meaning that as much as we like to chalk up our circumstances to genetics, we can actually help shape how our genes function with what we eat.4

Scientifically, we have seen the food-as-medicine answer play out time and time again. In a recent study that examined more than 700,000 people who had died from cardiovascular diseases (the leading cause of death in the world) as well as diabetes, more than half were associated with dietary factors like eating too much processed and red meat, unhealthy fat, and simple carbohydrates and sugar.5

Or how about cancer? Approximately one in five people will die from the growth of these abnormal cells, and a third of us will discover a cancer in our lifetime.6 But research suggests that only 5 percent of cancers are unavoidable. The rest—the 95 percent—are the result of lifestyle and environmental choices. This, in turn, means they can be prevented. Experts estimate that about a third of cancer cases are linked to what you eat.7 From brain dysfunction to stroke and arthritis, your food choices are a major determinant of not only your rate of aging, but also the quality of your life.

(Note: Food isn’t the solution to every health issue; as much as we’d like it to be so, simply eating an apple will not alleviate an arterial blockage. The truth is that medical interventions are necessary and are sometimes the frontline answer. But food is our number one disease preventer, energy provider, strength giver, and life sustainer, and should be treated as such.)

2. Timing Matters. Yes, you will achieve wonders if you can change what you eat by consuming more healthy nutrients and less unhealthy ones. But the when part? That’s the unsung hero of the diet narrative. By syncing up our food habits with our subconscious bodily preferences, we’ll have created the proverbial well-oiled machine (extra-virgin olive oil, please).

The skinny on timing, which we will outline in Chapter 1, comes down to just two simple shifts. Make these changes and eat foods that are loaded with good-for-you macronutrients, vitamins, minerals, and other compounds, and you’ll have set yourself up to build a body that lasts a long, long time. We’ll outline how you can get there. And we’ll even teach you one of the best techniques: stopping the stereotyping of foods (this page).

3. Give Taste a Chance. One of the most frustrating pieces of health dogma is that healthy food has to taste like dog food. Not true! Healthy eating does not mean meals that come in cardboard boxes or taste like cardboard boxes. Healthy eating does not mean boiled chicken every day of the week. Healthy eating does not mean you get so bored of the blandness that you feel the urge to dive tongue-first into a bag of M&Ms.

Healthy eating is about experimenting with new things, like spices, to augment flavors and find new definitions of sweet, spicy, and umami.

Healthy eating is about learning to cook with techniques that foster health, not because you have to, but because you want to.

Healthy eating is about simplifying your meals so that you spend less time preparing and more time savoring.

Healthy eating is about the joy of taste—and the joy of knowing that the investment you just made in your meal will pay dividends today, tomorrow, and decades from now.

To get there, we’ve broken down “when” into two types of timing:

When to Eat What—Your daily routine. We will explore how the most healthful foods interact with your body depending on when you eat them, yielding a smart blueprint for the very best way to eat each day.

What to Eat When—Your best choices for specific situations. We will also explore a variety of common life scenarios so that you can adjust your food choices to prevent and cure ailments, live optimally, and find success. For instance, what do you eat when you’re at risk of heart disease or cancer? Or when you’re hangry or stressed? Or when you just finished a great workout or are preparing for an interview? You see, our body’s internal environment is always changing—and how you feed it during those changes matters. Our goal is to tell you what to eat to best help your body, no matter what situation you’re in. When isn’t just about time of day; when is the ever evolving ecosystem that is the human body.

As you go through this book—and ease into a new way of eating with our simple 31-day plan—we promise that you’ll never look at food the same way again. Or clocks, for that matter. Tick tock, we don’t want your body to stop!

In these pages, we will bring you everything you need to know to help align your food choices with your body’s rhythms. You’ll find that it’s easy to nudge your lifestyle and your eating patterns in this direction. To that end, we’ll provide you with the following:

So as you embark on your journey of exploring the when and the what, how about we get started with how?

| PART 1 | How Food Works