The Pegan Diet

Introduction

Do we really need another diet book? No. Despite the title, the Pegan Diet is an un-diet—a simple set of principles blending science and common sense into guidelines promoting health, weight loss, and longevity that can easily be adapted to any philosophical or cultural preferences. What do we know about food? How do we know it? What conclusions can we draw from the data? How do we combine that with dietary, philosophical, social, and cultural preferences? As a physician on the front lines of the epidemic of chronic disease and obesity (one who has used food as the primary medicine in treating disease and optimization of health for 30 years), I am saddened by the diet wars and fad diets. Politics, religion, and nutrition are all equally polarizing.

The Pegan Diet started off as a joke. Years ago I sat on a nutrition panel at a conference between two friends—one doctor a Paleo proponent, and the other a vegan cardiologist. They argued vigorously for their points of view. To break the tension, I quipped, “Well, if you are Paleo and you are vegan, then I must be Pegan.” Thus it all began. As I started to think more deeply about what I had said as a joke, I realized that most dietary philosophies, including Paleo and vegan, had far more in common with one another than most people realize, and far, far more in common with one another than with the Standard American Diet, otherwise known as the SAD diet.

In fact, Paleo and vegan camps (if we stick to the best in both approaches) are identical except for one thing: where to get protein. Animal products or beans and grains? That’s it. Of course, you can be a chips and soda vegan, or a bacon and no veggies Paleo eater, but the best whole food expressions of each are so similar. Both promote a plant-rich whole foods diet; a diet low in starch and sugar, processed food, additives, hormones, antibiotics, GMOs; and, except for a small group of extreme low-fat vegan fans, a diet rich in good fats. They both even eschew dairy. And all the other dietary approaches—vegetarian, keto, time-restricted eating, lectin-free diets, Mediterranean, low-carb, low-fat, gluten-free, and more—mostly adhere to a whole foods approach and remove harmful ultra-processed foods and include protective foods.

Perhaps the real focus should be on shifting people from an obesogenic, disease-causing, nutrient-depleted diet to one rich in whole foods and protective foods that promote weight loss, health, and well-being. That, my friends, is the goal of the Pegan Diet.

Why is this more important than ever? Our modern industrial diet is currently the biggest killer on the planet, exceeding smoking and every other cause. Conservatively our modern diet, rich in processed foods made from wheat (white flour), corn (high-fructose corn syrup and many industrial food additives), and soy (soybean oil), and lacking in protective, healing whole foods (fruits, vegetables, nuts, seeds, whole grains, beans, seafood, etc.), kills 11 million people a year. I believe that is a gross underestimate. Each year about 57 million people die around the world. Three-quarters of those deaths (or 42 million) are due to chronic diseases such as heart disease, diabetes, cancer, and dementia, mostly caused by poor diet. Even infectious diseases, like COVID-19, are more likely to sicken and kill those who are overweight or suffer from chronic disease. The costs are staggering. In the United States, the direct and indirect cost for chronic disease is projected to be $95 trillion over the next 35 years, or about 1 in 5 dollars of our entire economy. Globally it’s much more, and getting worse as we export our American diet to every part of the globe.

If we want to lower the total burden of chronic disease, survive another pandemic, save our planet and communities, and create a happier, less divided society, we have to overhaul the way that we grow, produce, distribute, and consume food around the world. We have to come together, stop the diet wars, and embrace the healing power of proper nutrition. That is why I wrote this book—to showcase the power of food and present an inclusive and sustainable food philosophy.

The Pegan Diet is unique in four ways. I’ll cover each foundational principle next.

THE PEGAN DIET TREATS FOOD AS MEDICINE

The first foundation is this: Food is medicine, with both the power to heal and the power to harm. The best strategy for a long and healthy life is to eat your medicine—get your drugs at the farmacy, not the pharmacy! Food is far more than just calories or energy to fuel our bodies. It is information, instructions that regulate every function of our bodies in real time. Remarkable discoveries over the last few decades now enable us to use food not just for pleasure, joy, connection, and nourishment but also for rejuvenation, thriving, and even reversing disease. Quality and nutrient density are foundational to building a thriving human community. Some suggest we should all be nutrivores, prioritizing nutrient density; others propose we become qualitarians and focus on quality, no matter what dietary philosophy we hold. One discovery embodied in the Pegan Diet is that we are all unique, not just in terms of our preferences but also in our biology. Our genetic and biochemical uniqueness can guide us toward personalized nutrition. Despite our personal beliefs, some may thrive on a vegan diet; others may wither. Some become superhuman on a Paleo diet, and others not so much. The key is to explore your biology, not stay fixed in a particular ideology.

We are just beginning to understand how food influences our cells, tissues, organs, moods, thoughts, feelings, and the structure of our bodies, but what scientists have discovered over the last few decades is astonishing. Food is not only a source of energy, joy, connection, and pleasure; it can also rejuvenate us and even reverse disease. When we think of food, we think of protein, carbohydrates, fats, fiber, vitamins, and minerals. But the most important parts of food may be the tens of thousands of medicinal compounds embedded in plants and even animal foods that regulate, modulate, and influence nearly all of the 37 billion billion chemical reactions that occur in our bodies every second. I call this process symbiotic-phytoadaptation. It means our bodies use chemicals found in food to beneficially influence each of our biological systems.

Through evolution, we have borrowed the molecular magic embedded in foods to optimize and supercharge our biology. For example, we can’t synthesize vitamin C or omega-3 fats; we have to get these from nature. And it’s not just the obvious essential fatty acids, amino acids, and vitamins and minerals we get from our food; we also get important molecules called phytochemicals.

There are 25,000-plus phytochemicals in the plant kingdom identified to date, and they’ve only recently been deemed critical for health. Surprisingly they are also found in animals, such as in grass-fed cows, who consume a wide array of nutrient-dense plant foods. While deficiency of these phytochemicals may not result in an acute disease like scurvy or rickets or in protein malnutrition, it can lead to long-latency deficiency diseases such as heart disease, diabetes, hypertension, obesity, dementia, depression, and more.

The only way to take advantage of these disease-fighting compounds is to focus on our food quality. Deeply colorful plant foods, organic and grass-fed meats, and wild fatty fish are abundant in compounds that protect our cells and fight off invaders. If you eat industrial food, even vegetables, your diet will be depleted. Organic vegetables are more nutrient-dense. Factory-farmed cows fed a simplified diet of corn, cow poop, candy, and ground-up animal parts produce meat that leads to inflammation and disease. Wild elk or regeneratively raised cows that forage on dozens of medical plants produce meat that has the opposite effect.

Every time you take a bite of food, consider that you are programming your biology for health or disease. When you eat healthy food, you are, in fact, eating medicine.

THE PEGAN DIET IS BASED ON FUNCTIONAL MEDICINE

The greatest discovery of the last 50 years is that food is medicine with the power to prevent, treat, and even reverse most chronic disease (and quickly). This discovery is mostly ignored by traditional medicine. Is there an approach to medicine, disease treatment, and health creation that incorporates this new understanding? Yes. It is called functional medicine. It is what I have been practicing for nearly 30 years with remarkable, life-changing results. Functional medicine practitioners understand that what you put at the end of your fork is more powerful than anything you will ever find in a prescription bottle. It works faster, better, and cheaper, and all the side effects are good ones.

The body is a biological ecosystem, a network of dynamically interacting, interconnected systems. In conventional medicine they might say there’s a problem with your heart, liver, brain, or colon, for example. Diseases within each organ are viewed as separate and disconnected from the rest of the body. In functional medicine, we don’t view the body as a collection of isolated organs; instead the body is one network of systems. Treating disease means treating these systems or treating the root causes of imbalance. Functional medicine is the science of creating health, not simply treating the symptoms.

How do you treat the root cause and create health? It’s simple. Take out the bad stuff. Add the good stuff. The body’s natural intelligence and healing mechanisms do the rest. We start by removing the cause (or causes) and then replacing what the body needs to thrive. Almost all diseases (other than dominant inherited genetic conditions like Down syndrome) have the same few causes: toxins (both internal and external, such as pesticides, herbicides, plastics, heavy metals, and more), allergens (environmental and food), microbes (imbalances in bacteria—especially in the microbiome—as well as viruses, parasites, worms, and ticks), and poor diet and stress (physical or psychological). These triggers of disease interact with your genes and all your basic biological networks—your gut, immune system, hormones, brain chemistry, detoxification system, energy production, circulation, and even your body’s structure (cells, membranes, muscles, bones). In addition to the triggers of disease, there are necessary ingredients for health—real food, nutrients, hormones, light, water, air, rest, sleep, movement, love, connection, meaning, and purpose. These are the raw materials, each needed in proper balance, different for each individual, to create a healthy human. Creating health is simply a matter of identifying and removing the triggers and replacing the necessary ingredients.

Food, it turns out, is the biggest driver of imbalances in your biological networks and the biggest lever for rapid change, the reversal of disease, and the creation of health. While most doctors have not seen the power of food, mostly because they were not trained in using food as medicine, I have seen miracles over the decades, and so have thousands of functional medicine colleagues. I don’t even like to call them miracles. They result from applying the latest advances in understanding how our bodies actually work, not how we were trained in medical school. Autoimmune diseases disappear, depression vanishes, migraines evaporate, psoriasis and eczema clear up, Alzheimer’s patients’ memory improves, and type 2 diabetes disappears in a few weeks. These are not anomalies or spontaneous remissions but reproducible results based on applying food as medicine with the model of functional medicine.

Food is the most important tool in my medical toolbox. It works faster, works better, and is cheaper than medication. Applying food as medicine is the foundation of functional medicine. But you don’t have to see a functional medicine doctor to understand how to use food as medicine. The Pegan Diet was created to help anyone, anywhere, understand the power of nutrition and take steps to move toward better health today. You ingest pounds of foreign material into your body daily. If all calories were the same, it would not matter what you ate. But they are not. Food carries information molecules, instructions, and code that programs your biology with every bite for better or worse. Industrial food drives inflammation, triggers oxidative stress, promotes imbalances in hormone and brain chemistry, overloads your detoxification system, depletes your energy, damages your microbiome, and changes your gene expression to turn on disease-causing genes. Real, whole nutrient and phytonutrient–rich food does the opposite—turns off inflammation, increases antioxidant systems, balances hormones and brain chemistry, boosts detoxification, increases energy, optimizes your microbiome, and turns on disease-preventing, health-promoting genes.

Food impacts all these core systems or networks in the body. The Pegan Diet combines the latest science of food as medicine and strategies to optimize these systems into a practical way of eating for life.

THE PEGAN DIET SAVES YOU AND THE PLANET

Eating is an agricultural, environmental, and political act, not just a personal one. What we eat affects how food is grown, which food is grown, and which agricultural methods are used. Is our food grown in ways that produce the most nutrient-dense food, conserve water, build soil, reverse climate change, and increase the biodiversity of plants, insects, and animals? Or does it produce food that drives sickness and environmental destruction? Simply put, the Pegan Diet is a regenerative diet—one that regenerates human and planetary health. In other words, no matter what dietary approach we choose, we should all be regenetarians. That is something l believe we can all agree on. A diet that heals us, heals the environment and reverses climate change. Becoming a regenetarian might just save you and the world.

The food system is the number one cause of climate change, depletion of soil (we have sixty harvests left, according to the UN) and fresh water, and the loss of biodiversity of plants, animals, pollinators, insects, and even the microbiology of the soil. Our food system, which involves deforestation, soil erosion, factory farming of animals, agrochemical damage to the land, transport, refrigeration, and food waste, contributes about 50 percent of all greenhouse gas emissions. For example, soil is the biggest carbon sink on the planet, far greater than rainforests. It can hold 3 times the amount of carbon currently in the atmosphere, which is 1 trillion tons. In fact, of that 1 trillion tons of carbon driving climate change, one-third comes from the loss of soil carbon through erosion and destruction of soil life. The 400 billion pounds of nitrogen fertilizers are another major driver of climate change. They require about 2 percent of all global fossil fuel production to produce (mostly as fracking-derived natural gas). When applied to the soil, nitrogen fertilizers kill the microbial life and produce nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide.

These problems start with our food system, and so do the solutions. I have detailed both the problems and the solutions in my book Food Fix: How to Save Our Health, Our Communities, and Our Planet—One Bite at a Time. And I am working to change the policies that drive the system with the Food Fix Campaign (foodfix.org). The critical first step is to become a regenetarian (more on that in Principle 9: Eat Like a Regenetarian). The more people demand change, the more the system will change.

Large companies have stepped in where the government has not, funding conventional farmers to convert their farms to regenerative agriculture. This way of producing food is the antidote to our current farming system, which produces massive quantities of commodity crops that sicken humans and the planet. Regenerative agriculture raises food in a way that restores soil, conserves water, increases biodiversity, reverses climate change, produces more nutrient-dense, phytonutrient-rich quality food, all while making farmers far more money and making their farms resistant to drought, floods, and climate impacts. In short, it stops the cycle of destruction.

The large agribusiness companies frighten us by making us believe that we cannot feed the growing global population without them. The science does not support this claim. In fact, localized regenerative farming ecosystems are scalable globally and are the only true solution to food production in the future. Regenerative agriculture is the future of food. And each of us can play a role.

THE PEGAN DIET IS AN INCLUSIVE, FLEXIBLE WAY OF EATING FOR LIFE

Finally, the Pegan Diet is a way to eat for life. Most diets fail because they are restrictive, confusing, and leave us feeling ashamed when we fall off the wagon. The Pegan Diet is sustainable because it’s not about being perfect; it’s about feeding your body nutritionally dense food 90 percent of the time and leaving room for pleasure foods and treats (but still real-food treats). I am not perfect, and I don’t expect anyone else to be either. We all have families, social events, parties where we want to enjoy a margarita and a slice of cake. We can feed ourselves well, take care of our bodies, and enjoy life’s pleasures. Setting yourself up for success involves incorporating the right habits, getting the family involved, and learning to cook, which I promise can become anyone’s favorite activity.

I’ve tried nearly every diet on myself (and my patients). I’ve been vegan, Paleo, high-fat, low-fat, raw food, you name it. What I’ve come to learn is that you don’t have to define your diet. Instead, do what makes you feel good. Listen to your body. In the Pegan Diet I have created a set of simple, sane principles to guide you, but I hope that we will all eat this way one day without needing to give it a name. I want the Pegan Diet to be sustainable for anyone, anywhere. If you eat meat, you can follow this diet. If you don’t eat meat, you can follow these principles. If you’re just getting started on your health journey, it’s a great place to begin! If you’ve experimented with many diets but are still frustrated or confused or don’t feel well, this is for you.

Eating is the most important act we perform every day. It’s an act that connects us to nature, ecological cycles, biological functions, and, of course, one another. We are part of a great web of nature that provides the raw materials for creating a vibrant, healthy life.

In the following pages, you’ll find 21 Practical Principles for Reclaiming Your Health in a Nutritionally Confusing World. These principles provide a road map, guiding you toward a personalized approach to eating in a way that is good for you, your family, your community, and the planet. And, more importantly, that is delicious, nourishing, and joyful.