Show 1444: The Food Fight Over Fat: Keto and Carnivore Diets

For the last several decades, nutrition scientists have been debating the pros and cons of various dietary approaches. The Mediterranean diet has a lot of proponents, and we have interviewed some of them on The People’s Pharmacy. Dr. Barry Popkin and Dr. Walter Willett endorse olive oil, whole grains, fruits and vegetables with only small amounts of animal-sourced food. Listen to Show 1359: Is the Food on Your Plate Real or Fake? for more information. Dr. Will Bulsiewicz is a fiber evangelist. You can hear him on Show 1312: fiber, Phytonutrients and Healthy Soil. Plant-based diets can fall along a spectrum from mostly plants with some meat, fish and eggs to completely vegan. In contrast, there are experts who recommend a low-carb, high-fat ketogenic diet. Carnivore diets consisting of only animal products (meat, poultry, fish) are a subcategory of keto diets. That is the focus of this episode.

Carnivore Controversy:

We know that people have strong feelings about food. The DIETFITS study, one of the best randomized controlled trials comparing healthy low-carb to healthy low-fat diets found that both led to weight loss. Learn more by listening to our interview with lead investigator Dr. Christopher Gardner on Show 1126: Can You Find Your Best Diet? We have heard from fans of ultra-low-fat diets like those promoted by Pritikin or Dean Ornish, MD. We acknowledge that hearing about a carnivore diet may put their teeth on edge, at the very least. But information from knowledgeable sources about controversial topics is what we aim for, and this is indisputably controversial.

At The People’s Pharmacy, we strive to bring you up to date, rigorously researched insights and conversations about health, medicine, wellness and health policies and health systems. While these conversations intend to offer insight and perspective, the content is provided solely for informational and educational purposes. Please consult your healthcare provider before making any changes to your medical care, treatment, or diet.

Ketogenic and Carnivore Diets:

Doctors have long prescribed ketogenic diets to treat children with hard-to-treat epilepsy (Epilepsy & Behavior, Sep. 8, 2025).  Studies suggest that people with migraines or depression might benefit from a ketogenic diet (Brain and Behavior, Sep. 2025; Translational Psychiatry, Sep. 10, 2025).
Most people now following carnivore diets, which are more extreme than ketogenic diets, began following this eating plan to lose weight and have more energy. Our co-host for this show, AAAS Mass Media Fellow Bianca Garcia, has done some investigation of this approach to nutrition, including a personal trial. She joined us in interviewing Dr. Eric Westman, an advocate for ketogenic and carnivore diets to help people with obesity and diabetes.

What is a ketogenic diet? It minimizes the carbohydrate available as fuel by including only low-starch vegetables such as greens. High-fat food sources make up the bulk of the energy in the diet. This forces the body to burn ketones derived from body fat instead of glucose derived from sugar or starch. In a carnivore diet, the vegetables disappear completely and the high-fat food sources are all derived from animals.

How Do Dietary Guidelines Mesh with Carnivore Diets?

We asked Dr. Westman about changing dietary guidelines, and he pointed out that most of the national dietary guidelines have limited scientific support. Of course, randomized controlled trials of people following carnivore diets are also few and far between. A survey of more than 2,000 self-selected volunteers following the diet was published in 2021 (Current Developments in Nutrition, Nov. 2, 2021). The DIETFITS trial, which compared a healthy low-fat, high-carb regimen to one high in fat and low in carbs found no significant difference in weight loss over the course of a year (JAMA, Feb. 20, 2018).

What Are the Effects of a High-Fat Diet?

In the clinical trials he conducted, Dr. Westman found that blood insulin levels were lower as people followed a ketogenic diet (Expert Review of Endocrinology & Metabolism, Sep. 2018). The body does not require insulin to utilize ketones for fuel. As a result, people with type 2 diabetes have better control of their blood glucose when following a low-carbohydrate ketogenic diet (Nutrition & Metabolism, Dec. 19, 2008).

He and his colleagues have published a case series suggesting that a ketogenic diet could help people with food addiction (Journal of Eating Disorders, Jan. 29, 2020). There are also hints that people with other psychiatric conditions might benefit from a ketogenic diet as well (Psychiatry Research, May 2024).

What Is Driving the Interest in Carnivore Diets?

Bianca Garcia and Dr. Eric Westman agree that the internet has a huge influence on people’s interest in carnivore diets. Podcasters like Joe Rogan and multiple influencers have promoted this approach, especially to younger people. This can contribute to social pressure to try it. Dr. Westman warns listeners that adopting a ketogenic or carnivore diet should be undertaken under knowledgeable guidance. A drastic dietary change can alter how medications work, so people with chronic illness really need to work closely with health care professionals. That may require searching for someone who is open to this approach with the expertise to recommend when supplements or salt might be needed and provide information on doses.

This Week’s Guest:

Eric Westman MD, MHS, is an Associate Professor of Medicine at Duke University. He is Board Certified in Obesity Medicine and Internal Medicine and founded the Duke Keto Medicine Clinic in 2006 after conducting clinical research regarding low-carbohydrate ketogenic diets. Dr. Westman is a past President and Master Fellow of the Obesity Medicine Association and Fellow of the Obesity Society. He is a board member of the Society of Metabolic Health Practitioners and the American Diabetes Society. In addition, he has written and edited numerous bestselling books and is a co-founder of Adapt Your Life Academy (www.adaptyourlifeacademy.com), which provides science-backed education on a range of subjects rooted in the therapeutic effects of dietary carbohydrate restriction… including his newest course, Carnivore Made Simple, which is open now for enrollment for a limited time.

Eric Westman, MD, Duke University

Our Co-Host:

Bianca Garcia is a Filipina-American anthropologist, foodie, and radio person. She holds a master’s degree in Media, Medicine, and Health from Harvard Medical School, where she created an audio documentary on the carnivore diet. She was a AAAS Mass Media Fellow covering health and science at WUNC, North Carolina Public Radio when we conducted the interview; her favorite stories to cover always involve what people eat, and why.

Bianca Garcia, photo copyright Christina Thompson Lively

Listen to the Podcast:

The podcast of this program will be available Monday, Sept. 15, 2025, after broadcast on Sept. 13. You can stream the show from this site and download the podcast for free, or you can find it on your favorite platform.

In the podcast for this episode, you’ll hear the real patient story of a doctor who weighed 350 pounds and suffered from POTS (postural orthostatic tachycardia syndrome). Do we have any idea of how a carnivore diet affects the gut microbiome? Dr. Westman describes his study on how a low-carb diet helps GERD (gastroesophageal reflux disease). Years ago, Joe looked for evidence on the traditional heartburn diet limiting fat, alcohol, coffee and tomatoes and couldn’t find any. What we have found is that science changes as researchers pursue further studies and that is not a reason to mistrust science even though the changing recommendations may be frustrating. Dr. Westman offers a message to everyone trying to make the right dietary choices but feeling overwhelmed by many different messages about food.

Citations

• Carroll JH et al, "Over twenty-five years of ketogenic diet therapy: Supporting children and adults with drug-resistant epilepsy using nutritionally complete ketogenic formulations: A scoping review." Epilepsy & Behavior, Sep. 8, 2025. DOI: 10.1016/j.yebeh.2025.110683
• Gunasekera L et al, "The Hypometabolic State of the Migraine Brain: Is a Ketogenic Diet the Answer?" Brain and Behavior, Sep. 2025. DOI: 10.1002/brb3.70860
• Decker DD et al, "A pilot study examining a ketogenic diet as an adjunct therapy in college students with major depressive disorder." Translational Psychiatry, Sep. 10, 2025. DOI: 10.1038/s41398-025-03544-8
• Lennerz BS et al, "Behavioral Characteristics and Self-Reported Health Status among 2029 Adults Consuming a "Carnivore Diet"." Current Developments in Nutrition, Nov. 2, 2021. DOI: 10.1093/cdn/nzab133
• Gardner CD et al, "Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion: The DIETFITS Randomized Clinical Trial." JAMA, Feb. 20, 2018. DOI: 10.1001/jama.2018.0245
• Westman EC et al, "Implementing a low-carbohydrate, ketogenic diet to manage type 2 diabetes mellitus." Expert Review of Endocrinology & Metabolism, Sep. 2018. DOI: 10.1080/17446651.2018.1523713
• Westman EC et al, "The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus." Nutrition & Metabolism, Dec. 19, 2008. DOI: 10.1186/1743-7075-5-36
• Carmen M et al, "Treating binge eating and food addiction symptoms with low-carbohydrate Ketogenic diets: a case series." Journal of Eating Disorders, Jan. 29, 2020. DOI: 10.1186/s40337-020-0278-7
• Sethi S et al, "Ketogenic Diet Intervention on Metabolic and Psychiatric Health in Bipolar and Schizophrenia: A Pilot Trial." Psychiatry Research, May 2024. DOI: 10.1016/j.psychres.2024.115866