Author of “Truth About Food” Reveals 3 Truths to End All Confusion About a Healthy Diet


Author of “Truth About Food” Reveals 3 Truths to End All Confusion About a Healthy Diet…


David L. Katz, MD, MPH, FACPM, FACP, FACLM is the founding director of Yale University’s Yale-Griffin Prevention Research Center, Immediate Past-President of the American College of Lifestyle Medicine, Founder/President of the True Health Initiative, and author of The Flavour Point Diet, The Way to Eat, Disease Proof, and his newest book, The Truth About Food, all profits from his books go to charity.

Blue Zones: Tell us about your newest book, The Truth About Food.  What is the truth?

Dr. David Katz: I wrote The Truth about Food because there’s a problem with the current dialog about nutrition—whether it’s morning shows, diet books, or even the scientific literature. People are fed a little bit of truth at a time, and also usually just one perspective at a time. So if someone wants to make the case for one diet, they make the case for that kind of diet. The result is unending confusion and consequently, as a culture, we’ve totally lost our way about diet and health.

There’s more than one way to eat badly and the American culture seems committed to trying them all.

BZ: How do we combat the constantly conflicting nutritional advice covered in the news and on TV?

DK: The headlines make it seem like the scientific community is lost and confused about diet and nutrition. That’s not the case.

TRUTH #1:  One thing I wanted to make clear is that there is no confusion among experts.

People argue over the details but miss the big picture. Some might get differing advice from their doctor or their trainer or their friend over social media, but you shouldn’t rely on one person’s opinion. The world’s foremost experts are in agreement.

The True Health Initiative, which I founded, is a coalition of world-renowned and diverse experts who have come together and agreed on the simple and actionable fundamental truths about diet and health. These experts are the who’s who in science and nutrition—leaders in the public health space, three former Surgeon Generals, the former Chair of Nutrition at the Harvard School of Public Health, the former director of the Cleveland Clinic, and so on. If your doctor was going to a conference to learn about nutrition science, these are the people that he or she would learn from.

BZ: What is the global consensus?

DK: There is a clear global consensus from the world’s nutrition scientists and experts about the healthiest dietary pattern. This pattern, unsurprisingly, is how Blue Zones centenarians ate for most of their lives.

TRUTH #2:  A diet high in plant foods (beans, vegetables, nuts, fruit, whole grains) and low in processed foods is best for health and longevity.


TRUTH #3: Over 80% of chronic disease and premature death could be prevented by following this healthy dietary pattern, getting regular physical activity, and not smoking.

BZ: That’s all very clear, but not very clickworthy. Do you think the need for attention-grabbing headlines are mostly to blame for all this confusion?

DK: The other thing is active deception. Some of the misleading headlines are entirely on purpose. The Big Food industry wants people to be confused about diet, and the pharmaceutical industry (Big Pharma) doesn’t care that people are confused either. In my book, I’ve devoted whole sections to lies, damn lies, and statistics.

BZ:  What is the biggest takeaway you want readers to get from the book?

DK: The book is 780 pages because I don’t want to just tell the readers what I know. I want to immunize readers not just from today’s fad diet, but also from tomorrow’s fad diet. By showing them how to differentiate truth from lies,  I’m empowering people to be able to tell what is or is not reliable information.

I also wrote it as a resource for public and professional colleagues. Until we have better nutrition education in medical schools (currently there is little to none), we need to help practitioners have the best information too.

BZ: In our Blue Zones Project communities, we focus first on changing policy so our environments support healthy behaviors. In our current foodscape, it’s hard to rely on individual behavior change when willpower runs out. How can people combat the endless buffet of cheap, high-calories foods that are everywhere?

DK: I still think individuals have the power to change. Skillpower is the neglected cousin of willpower. People can master things if they have a set of skills and learn to use them. So helping people identify nutritious foods that are inexpensive and easy to make like beans and lentils are an example of giving people skills. The next step is giving them step by step guidance for learning how to make delicious dishes.  

BZ: Your article with Mark Bittman in Grub Street got a lot of people talking. How did that come about?

DK: It actually came from our own conversations, and got so much interest that we’re now working on a book together. It will be a conversational approach to these topics, while The Truth About Food is more of a comprehensive reference.

BZ: What do you think is the most dangerous nutrition myth or fad out there today?

DK: If I had to say one, then probably the keto diet. But the most dangerous nutrition myth is that the world’s experts are confused about diet and health.

BZ: In our work, we always try to focus on eating for health and longevity, not for weight loss. That seems to be a distinction that even some health publications confuse often.

DK: Yes, I always say that a cocaine binge or cholera will result in rapid weight loss. Just focusing on losing weight will not yield better health. 

BZ: What else is new for you?

DK: I’m working on a new technology right now called Diet ID  that could help people easily assess their dietary pattern. I believe it could transform nutritional epidemiology because we tend to manage the things we measure.

BZ: What are some of your favorite meals?

DK: It’s hard to pick because my wife’s a spectacular cook. She was born in North Africa and raised in Southern France, so cooks incredible Mediterranean dishes. I love her tagine and her vegetarian chili. You can find the Katz family’s favorite meals on her website.

BZ: What’s your guilty pleasure?

DK: When I’m in Paris, a great crusty bread, a glass of fine red wine, and some fine goat cheese is my meal for absolutely gustatory pleasure.

But I don’t like or crave junk. When I indulge, it’s rare and not on fast food.

BZ: What are you most proud of?

DK: I’m most proud of trying so hard for so long to disseminate the fundamental truths that can add years to lives and lives to years. It’s hard. If you’re out there, you get attacked. I have a pack of trolls and it gets worse and worse every year. I started this path a couple decades ago, and made it my mission to reduce chronic disease. Now we have more chronic disease than ever.

I have a wife and children. I know what it means to love other people and want them to have the best possible destiny. So it’s mission critical and I don’t plan on giving up. I’m soldiering on.


David L. Katz, MD, MPH, FACPM, FACP, FACLM earned his BA degree from Dartmouth College; his MD from the Albert Einstein College of Medicine; and his MPH from the Yale University School of Public Health.  He completed sequential residency training in Internal Medicine, and Preventive Medicine/Public Health and is board certified in both disciplines.

He is the founding director of Yale University’s Yale-Griffin Prevention Research Center, Immediate Past-President of the American College of Lifestyle Medicine, and Founder/President of the True Health Initiative, and the author of roughly 200 scientific articles and textbook chapters, and 15 books to date, including multiple editions of leading textbooks in preventive medicine, nutrition, epidemiology, and biostatistics.