Ray Cronise on the Science Behind Why Plant-Based Diets Rule

June 7, 2018

Are plant-based diets really better for you? We talked to scientist, author, and diet coach Ray Cronise to find out.

I asked one of our writers for a Ray Cronise interview way back in 2015 because his unorthodox plan, his ability to rethink nutritional norms using evidence-based exploration, and his many passionate supporters (called Cro-Nuts) intrigued me. Cronise is a former NASA scientist and superstar in the weight-loss world, and he’s the brains behind the success of many celebrity transformations—as well as the weight-loss successes of regular Joes. In February, “Clerks” director Kevin Smith revealed he had suffered a massive heart attack, and initially credited Cronise and our friend Penn Jillette with his rapid weight loss and improved blood-pressure levels.*
Cronise—whose latest project, JustSides.com, offers tasty plant-based side dish recipes—also provides personal weight-loss coaching, and he’s made headlines with his “potato diet.” And while headlines are good for business, “the potato diet” isn’t a thing, really. Yes, Cronise is known to recommend a “mono diet” at the start of his weight loss plan as a tastebud reset, but it doesn’t last long, and it doesn’t begin to explain the core of his beliefs—a lifestyle change to a plant-based diet for optimal health.

Cronise’s new book, Plant-Based Nutrition, penned with Julieanna Hever (both pictured above), who’s a registered dietitian and has a master’s degree in nutrition, makes this clear. It’s an update on the first Idiot’s Guide, and it goes way beyond potatoes. The book contains a lot of good science and includes a side of recipes from celebrity chefs, as well as anecdotes from notable people who say they’ve benefited from the lifestyle, including Jillette, who wrote the intro—which is funny and sticks the landing, natch.
Although I’m not 100% plant-based yet, I loved the book and found it inspirational, and this bit buried on page 183 in the chapter titled “Winning at Weight Loss” really struck me:
“We’ve been deluded to think that all this swallowing and wiggling is the secret to success. People want to blame the battle on food deserts, knee injuries, GMOs, broken metabolisms, and hormones. The reality is that a century ago, food was economically scarce and many handed-down, traditional recipes are built from the bottom of the Food Triangle. That’s a plus when food is scarce. But, today, it is maladaptive.”

Interview with Ray Cronise, 2e

For our second interview, I asked Cronise a few follow-up questions ranging from his motivation to his advice for people who struggle with this change. I also asked if we could share a recipe at the end, and he said yes. So come for the science—but stay for the snazzy beans.

Q: With so much nutrition advice already out there, what inspired you to write this book?

Julieanna wrote the first edition in 2011, and it was a big hit for the Idiot’s Guide series. The two of us began working together in late 2016 and had our first peer-reviewed journal article published in the Journal of Geriatric Cardiology in early 2017: “Plant-based nutrition for healthcare professionals: implementing diet as a primary modality in the prevention and treatment of chronic disease.” We came to this from completely different perspectives—one focused on clinical side of plant-based nutrition and the other on healthspan/longevity.  As we wrote the paper, it became clear that the messages not only resonated, but were unbelievably synergistic.
So many people approach nutrition from the vantage point of being deficient—this idea, after all, was present at the birth of nutrition more than a century ago, when food was economically limited. Today, however, the number of chronically overnourished outnumber the undernourished. It’s malnourishment—too much nutrition—that is often overlooked in the clinical setting. Healthspan research all seems to be pointing to the idea that less is more. A whole-food, plant-based diet seems to mimic these healthspan-promoting effects seen in longevity research.

In short, why do you believe following a plant-based diet is best for long-term health?

A plant-based diet is the only diet shown to reverse advanced cardiovascular disease and type 2 diabetes and has been associated with a decreased risk of hypertension, high blood cholesterol, obesity, certain cancers, and most chronic diseases. Further, swapping out animal products and processed foods for whole plant foods supports immune function by improving the microbiome and offers a high nutrient load without excessive calories. Plant-based diets are also associated with a reduction of common non-specific symptoms, such as heartburn, irritable bowel syndrome, acne, sleep apnea, eczema, and more.

What advice would you give to those who are interested in eating a more plant-based diet, but are struggling to make the transition?

 It’s easy to invent worry out of perceived loss, but recognize that most of the plate is already plants. Many traditional side dishes were the main course when food was less abundant and only the affluent were chronically overnourished. As of 2011, the overnourished outnumber the undernourished for the first time in history. Obesity is now a symptom of poverty, and most of that is due to the availability of hyperpalatable foods. While everyone is worried about “getting enough,” nutritionally speaking, people cut their lives short by eating too much. Some of that behavior is likely due to the drumbeat of frequent meals and adequate protein, when, in fact, nutritional deficiency diseases that were common a century ago, like scurvy, rickets, and pellagra, aren’t very common in modern times. We use deficiency prevention as a basis for nutritional education, and yet most people are dying early of nutritionally induced diseases of excess. Our advice is to simply find whole food, plant-based recipes you love and to build your repertoire of healthy meals.

What are some of the most important nutritional considerations to keep in mind for those who want to eat a more plant-based diet?

 The most important myth we shatter is the idea that adding animal products to the plate somehow makes a plate nutritionally complete. Nothing could be further from the truth. We hear people clamoring about “protein,” and yet most don’t know that the tens of thousands of proteins (plural) are synthesized from just 20 amino acids. No animal makes all 20, and the 9 amino acids that must come from our diet are made by plants. All whole plant food contains all 20 amino acids, and this is why the 10 largest mammals walking the planet—including 5 rhinoceroses, 2 elephants, the hippopotamus, the giraffe, and the gaur—don’t eat animal flesh, and yet are still plenty muscular.
A diet rich in vegetables, fruits, whole grains, legumes, mushrooms, nuts, seeds, herbs, and spices has an abundance of healthy phytonutrients and restricts nutrients that may be detrimental to health.

What type of recipes will readers find in this book?

 We have a collection of about 45 delicious, simple, and nutritious recipes from the original book, and new ones from celebrity plant-based chefs. You will find a wide variety of dishes, from light fare to mouthwatering mains, and even sensational sweets like cookies and cakes.
Many thanks to Ray for his time, and for the recipe below, which is from their book. Fast and filled with only good stuff, it might just be your new summer groove.

Easy Beans and Quinoa

This warm and hearty one-pot wonder has a very Southwestern flair.

1 small yellow onion, chopped
2 medium cloves garlic, minced or crushed
1/4 cup vegetable broth
1/2 cup dry quinoa
1 (15-oz.) can no-salt-added pinto or black beans, rinsed and drained
1 cup water
1/2 tsp. ground cumin
1/4 tsp. sea salt (optional)
1/4 tsp. freshly ground black pepper
1/2 cup frozen corn kernels, thawed
1/4 cup chopped fresh cilantro


  1. In a medium pot over medium heat, saute onion and garlic in vegetable broth for 5 minutes or until onions are translucent.
  2. Add quinoa, beans, water, cumin, sea salt (if using), and black pepper. Bring to a boil, lower heat to low, and simmer for 20 minutes stirring frequently, or until all liquid is absorbed.
  3. Stir in corn and cilantro until heated through. Remove from heat and serve. 

*On the April 23, 2018, episode of “The Today Show,” Kevin Smith announced he was a new Weight Watchers ambassador.