Dr. Anthony Chaffee on Why Carnivore "Fails"

The Claim: "Carnivore Ruined My Health"

The story goes like this: someone eats carnivore for months or years. Their thyroid crashes. Their energy tanks. They add carbs back in and feel better. Carnivore must be the problem.

Chaffee's seen this narrative explode in the past year. His response is blunt: most of these people weren't doing carnivore at all.

What Chaffee Says Is Actually Going On

1. They Were Never Zero-Carb

"Some people who are the proponents of getting rid of ketogenic diets were never ketogenic before by their own admission. They said explicitly that they've never eaten less than 100 to 150 grams of carbs minimum per day."

Chaffee calls this "no man's land" — low enough carbs to spike insulin and block ketone production, but not low enough to actually enter ketosis. The result: reactive hypoglycemia, blocked fat burning, terrible energy. They blame carnivore, but they were never in ketosis.

2. Not Enough Fat

The Inuit ate 92% of their calories from fat. Pemmican — the original survival food — was 80% fat by calories (two grams of fat per one gram of protein).

Chaffee argues that modern carnivore dieters often eat too lean. When protein becomes your primary energy source without enough fat, the body has to break down amino acids. That process produces ammonia. Too much ammonia overwhelms the liver's ability to convert it to urea.

"You can lose your hair. You have very poor energy. You get very sick."

Add carbs back in and the ammonia problem disappears — because you're getting energy elsewhere. People feel better and blame carnivore. Chaffee says the problem was fat intake, not the diet itself.

3. Misreading Thyroid Markers

Lower T3 on carnivore looks like a problem on paper. Chaffee says it's actually efficiency.

His argument: ketones produce roughly three times more ATP (cellular energy) per unit of T3 than glucose does. If the body needs less T3 to produce the same energy, producing less T3 is a feature, not a defect. TSH and T4 staying normal confirms the system is working — it just needs less of the active hormone.

4. Tolerance Loss Mistaken for New Sensitivity

Stop eating plants for six months. Then eat a salad. You'll probably feel terrible.

Chaffee's explanation: you've lost tolerance to plant toxins. Your alarm system, which had been suppressed for survival purposes, is now working again. The rash, the inflammation, the MCAS symptoms — they're not new problems. They're your body recognizing what it was ignoring before.

"It's like alcohol tolerance. The first time you drink, you feel it. After years of drinking, you don't. Doesn't mean the alcohol stopped being harmful."

5. Confounding Factors

Alcohol. Sweeteners. Sleep deprivation. Stress. Excessive liver consumption (hypervitaminosis A). Medications like Accutane.

Chaffee points out that many high-profile "carnivore failures" had other factors in play. Someone takes a vitamin A analog while eating lots of liver, gets sick, and blames carnivore. Someone drinks regularly but claims they don't. Someone was never below 100g carbs.

"Look at the source. Does it pass the smell test?"

The Evidence He Cites

• National Academies of Science: "The amount of carbohydrates that people need is zero for their entire life."
• Inuit populations: Generations eating zero-carb without thyroid dysfunction or the developmental disorders that would result from endemic hypothyroidism.
• 70% of animals on Earth: Carnivores running on fat and protein.
• His own patient data: Over 1,000 patients tracked. Claims he's never seen the problems "quitters" describe when patients eat high-fat, fully plant-free, true zero-carb.

The Bottom Line

Chaffee's argument: most carnivore "failures" are actually protocol failures — not enough fat, not enough time, not actually zero-carb, or confounding factors blamed on the diet.

His evidence is compelling but not conclusive. Patient data without controls isn't proof. What's clear: if you're going to try carnivore and evaluate it fairly, Chaffee's failure patterns are worth knowing. Not enough fat. Not enough time. Not actually zero-carb. Confounding factors.

Whether carnivore is right for you — that's your call.