Paul Saladino with a plate of produce

Why Dr. Carnivore Changed His Mind About Meat-Only Diets

The carnivore diet once piqued the interest of many in the biohacking community. Now, the biggest advocate is quitting for good.
By Rebekah Harding
December 27, 2023

Functional medicine doctor Paul Saladino, M.D.—aka Dr. Carnivore—made waves in the biohacking community with his strict diet beliefs. But in 2023, Saladino’s health took a turn, prompting him to turn away from the diet that shaped his career. 

Saladino has been committed to a meat-only diet since 2018—selling books and diet programs to those interested in the alleged health benefits of the extreme, no-carb regimen. But in a recent interview with podcaster Thomas DeLauer, Saladino said that after five years on the carnivore diet his testosterone levels tanked. He also believes the diet is the cause of his sleep issues and joint and muscle pain. 

According to Sydney Greene, M.S., RDN, these health outcomes aren’t surprising—especially considering he followed the restrictive diet for half a decade. 

“Dr. Saladino was possibly deficient in nutrients that are responsible for producing important hormones like testosterone and melatonin,” Greene says. “Second, low glucose levels (a result of irregular carbohydrate intake) can cause heart palpitations.” 

When you eat a food with carbs in it, your body breaks it down into glucose, or blood sugar. It’s  your body’s main source of energy and plays an important role in maintaining normal physiological functions and overall health (1).

About the Expert

Sydney Greene, MS, RDN, is a registered dietitian and nutritionist. She specializes in nutrition for addiction recovery, eating disorders, and digestive struggles. She’s also passionate about debunking dangerous fad diets.

What Is a Carnivore Diet, Exactly?

A carnivore diet often consists of meat, fish, and animal-based foods, such as eggs and certain dairy items. But, there are a few variations of the carnivore diet, and Saladino followed one of the most intense of the bunch. For years, he exclusively ate organs and grass-fed ground beef. Saladino claimed that his meat-only diet cured him of hisautoimmune issues, like asthma and severe eczema. He went as far as to say that vegetables and tap water are loaded with toxins and that carbs, in general, aren’t good for your health. 

However, since he published his book The Carnivore Code in 2019, Saladino has wildly changed his views on carbs. Now, the former meat connoisseur incorporates 300 grams of carbs into his diet daily, largely by way of fruits. 

“It’s humbling. You put your thoughts into cement. And then you change your thoughts,” Saladino tells DeLauer. “I’ve learned that including carbohydrates in my diet improved my health.” 

However, he reportedly still avoids vegetables.

Still, many biohackers—as seen in the 62,000 members in the r/carnivore subreddit—remain loyal to this carbless diet, arguing that it can balance hormones, increase lifespan, and even offset the development of gray hair. But, is there any science to back up any of these supposed claims?

“The major benefits that have been suggested [by dieters] include weight loss, improved blood sugar markers, and resolution of skin and digestive issues. But, there is little to no research to back up any of these suggested benefits,” Greene says. 

She adds there’s minimal evidence that suggests a carnivore diet can improve your hormone health or increase your longevity. Not only does the carnivore diet lack science-backed benefits, but Greene says it could also pose a huge risk to your overall health if you choose to follow it.

“Those following the carnivore diet are more at risk for vitamin and mineral deficiencies due to the lack of variety in the diet,” Greene says. “Dieters are also at risk of having gastrointestinal issues such as constipation and acid reflux. The carnivore diet contains no fiber which [can damage] the gut microbiome by starving good bacteria in the gut.”

Saladino isn’t the only big-name biohacker that’s jumping ship from the carnivore diet. Dave Asprey, who is widely known as the Father of Biohacking and author of Smarter Not Harder, tried a meat-only meal plan for three months and says the lack of carbs and fiber wrecked his gut health and reduced his sleep quality.

Asprey says he initially felt fine on the diet. But then, after a couple of weeks, he noticed his sleep wasn’t as restorative as usual. 

“I was exhausted every morning. According to my sleep monitor EEG equipment, I was waking up 10 to 12 times per night without knowing it,” Asprey says. (For context, EEG equipment measures electrical activity in the brain when you’re awake and asleep.) He also experienced gastrointestinal discomfort when following the diet.

Since developing negative health outcomes from the carnivore diet, both Asprey and Saladino both advocate for low-carb, but less restrictive alternatives. However, Saladino won’t be committing to a balanced omnivore diet anytime soon. He now incorporates fruit, honey, and raw dairy into what he calls an “animal-based diet.” But even that level of restriction isn’t recommended by most health experts.

“I would never recommend this diet to anyone. The fact that a medical doctor was singing the praises of this diet is incredibly unethical,” Greene says. “Part of living a healthy life depends on having a varied diet. Including all food groups is important for mental and physical health.”

  1. Lappin, et al. (2022) Physiology, Glucose