Hey friend,

I wanted to do a small review on a diet I’ve noticed has been gaining in popularity: the Carnivore Diet.

The Carnivore Diet wasn’t created by researchers or any particular culture. Depending on who you ask, the diet was created by Shawn Baker (a former MD who lost his license) and popularized by the low-carb crowd and bodybuilders.

So what is the diet?

Unfortunately, there is quite a lot of disagreement as to what exactly defines the Carnivore Diet. The original true Carnivore Diet was exactly what it sounds like – don’t eat plants, only eat animals. But that seemed to be a bit too extreme for most practitioners, because now there are multiple offshoots with added foods. If you Google it, you’ll find some allow things like dairy and eggs, and some even allow certain plants! I’m not sure how you can claim to be a pure carnivore diet if you’re eating plants, but I guess that’s me arguing semantics.

What is the diet based on?

The diet is built around two central tenants:

  1. We should be eating like our ancestors.
  2. Carbs are evil.

You can see they borrowed from two other popular diets – claim #1 comes straight out of the paleo playbook, and claim #2 comes from keto.

I should point out that both of those claims in relation to a carnivore diet are completely false. Ancient human populations ate whatever was around. Sometimes that was mostly animals, and sometimes that was mostly plants. The Inuits are an example of one of the few groups of people who naturally eat a ‘mostly animal’ diet, but even they eat quite a bit of plants (berries, grasses, weeds, tubers, stems, seaweed, roots, etc.).

As far as claim #2 goes, carbs aren’t evil. The longest lived and healthiest populations on the planet all eat carbs. SOME carbs are problems for people – like sodas, candies, and other junk items. To label an entire category of food bad for health because some people have problems with some carbs is a logical fallacy (and downright egregious when you also add in the evidence showing massive health benefits to healthy sources of carbs like legumes and fruits).

What are the claims of the diet?

Pretty much everything you can think of. They say it’ll help you lose weight, be healthier, live longer, reduce anxiety and depression, help with gastrointestinal issues, and treat autoimmune conditions.

With a list like that, I’d be sold too if it were all true.

What does the science say?

It doesn’t. There are no clinical trials investigating this diet as of yet. However, we can make some inferences.

A ketogenic diet is already controversial due to its complete lack of dietary carbohydrate. You see that practitioners of a ketogenic diet are at increased risk for various nutritional deficiencies (among other issues like decreases in high-intensity exercise capacity and increased risk for injury and illness). However, proponents of the keto diet emphasize inclusion of lots of plant foods to shore up this glaring weakness.

The Carnivore Diet doesn’t care and goes ‘all in’ on eliminating plants, with the end result being a pretty significant risk to nutritional inadequacy and deficiency.

But my friend lost all this weight!

You bet they did. If they didn’t, the diet wouldn’t have nearly the popularity it does today.

There are several reasons for the weight loss:

  1. Going from not caring about your nutrition (like eating a standard Western Diet) to suddenly caring about it will produce results by itself, regardless of the diet type.
  2. The Carnivore Diet is high in protein, the most satiating of the macronutrients, which is great for staving off hunger during weight loss efforts.
  3. The Carnivore Diet eliminates carbohydrates. Each unit of stored carbohydrate binds 3 parts water. When your body burns through the stored carbs, the water also leaves. This leads to a rapid decrease in weight the first week. Note: Adherents won’t be losing any extra fat as a result of this, it is all water weight.
  4. The Carnivore Diet eliminates fiber. At any given time you have several pounds of still-digesting food moving through your gut. When you stop eating fiber and only eat easily digestible foods, your gut is no longer holding onto this residue.

Once carbs and fiber are re-introduced when you inevitably fall off the unsustainable diet (through no fault of your own), the water weight and gut residue will instantly come back.

But my friend’s stomach got better!

This one is interesting. I can think of two times where we actually prescribe a similar-ish diet:

  1. In the hospital to treat active GI flare-ups. During a flare-up, the goal is to rest your GI tract and allow it time to heal, so all hard-to-digest foods are removed (plant foods being a big component of this). It ensures nothing irritates the intestinal lining and also that no unpleasant bloating occurs.
  2. Before a colonoscopy. Only easy-to-digest foods are allowed so that the GI tract is completely empty before the procedure.

I believe that anyone struggling with GI issues will see acute benefits from the Carnivore Diet. If they aren’t struggling, they’ll still probably feel more ‘light’ on the diet due to the minimal residue and less gas production.

That all being said, active GI flare-ups and colonoscopies are NOT the norm. Under normal circumstances, we recommend a HIGH fiber diet. This helps protect the GI system in the long-term.

Gut microbiome

We’re only just starting to appreciate how critical a healthy gut microbiome is for normal human health, wellness, and performance. It’s been linked to every disease and process you can think of.

The bacteria living in your intestines eat what you don’t eat. Your body gets first dibs at the nutrients in food. We extract everything we can, and then hand the remainder over to our friendly neighborhood gut bugs. The stuff they end up getting is mostly fiber. They love fiber.

If you eat a no residue diet, you are starving all of your gut bugs. They’ll start looking for food nearby to eat and survive. The only thing around is the mucus layer separating your intestinal wall from them. They’ll start eating it to survive. Once your mucus layer is gone, they’ll start eating your intestinal wall. This leads to chronic inflammation and things like leaky gut. Not good.


Listen. If this diet helps you take a step toward better health, then I am all for it! However, don’t label it optimal. You need to keep going. There are some very clear weaknesses to the Carnivore Diet, like increasing risk for nutritional deficiencies and killing your gut microbiome.

I haven’t seen a single research study yet that has found plants to be bad for normal, healthy humans. If you are not a normal, healthy human and have some kind of clinical condition, then please speak with a registered dietitian who can put you on the correct kind of diet.

Thanks for reading. Let me know what you thought this week and let me know what else you’d like me to review!


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