
How Your Body Runs without Carbs: The Carnivore Diet (Part 2 of 2)
Video | Recap | Ketones | Carnivore Diet | PROs | CONs | Conclusion
If you’re like many people, you’ve found that cutting carbs is a great way to lose weight and improve the way you feel. So, if cutting back on carbs is beneficial, wouldn’t it be best to just stop eating carbs altogether?
There is a diet that lives by this philosophy called the Carnivore Diet. This post completes our two-part series on how your body runs without carbs by discussing the pros and cons of the Carnivore Diet.
How Your Body Runs Without Carbs (Part 2 of 2) – At-A-Glance
- Your brain not only runs on ketones, it thrives on them.
- The Carnivore Diet is a no-carb diet consisting of entirely animal products.
- Pros: Accelerated weight loss and ketosis
- Cons: Lack of food variety, not enough research on the long-term effects, possible negative impact on gut health, and possible nutrient deficiencies.
How Your Body Runs without Carbs: The Carnivore Diet [Video]
In this post, you’ll learn…
- The three main forms of energy that your body uses.
- The pros and cons of the carnivore diet.
- Whether or not the carnivore diet is necessary.
Recap of Part 1
Part one of this series explained how carbohydrates are used by your body for energy and how your body creates energy when you reduce or eliminate carbs from your diet.
In a nutshell, your body has three main forms of energy that it can utilize:
- Carbohydrates (or glucose)
- Free fatty acids
- Ketones
Glucose is a universal energy donor. This means that any cell in your body can take it in and use it for energy.
Free fatty acids are a different story. Because of their size, they are too big to cross over the blood-brain barrier, so your brain cannot take them in and use them for energy.
Fortunately, your brain is more than happy to run on ketones, which are an alternative energy source that your body produces in the absence of glucose.

Ketones: Your Alternative Energy
Your brain not only runs on ketones, it thrives on them. The origins of our modern-day ketogenic diet can be traced back to the 1920s when the diet was found to be successful in treating children with drug-resistant epilepsy, a seizure disorder caused by abnormal brain activity.
Beyond the benefits for the brain, research by prominent scientists like Drs. Thomas Seyfried, Stephen Phinney, and Dom D’Agostino is showing that ketones may have benefits ranging from cancer prevention to better athletic performance.
There are two things that will cause your body to make ketones:
- Very-low-carb diet
- Fasting
If you want to eat and make ketones, you will need to select foods that contain very few carbohydrates.
Plants make carbohydrates through a process called photosynthesis. We can make the broad statement that any food that comes from a plant contains carbohydrates.
Is the Carnivore Diet a Good Idea?
This is where we see the basis of the Carnivore Diet movement coming into the light. In essence, if you don’t want to eat carbs, don’t eat plants or things that come from plants like vegetables, nuts, seeds, and berries. Is this a good idea?

I will preface my comments by sharing that I’ve never followed a carnivore diet, and I was unable to find studies with human subjects or animal models that evaluated the long-term health impact of the diet. My points are based on anecdotal evidence and opinion.
PROs & CONS of The Carnivore Diet
With that said, let’s take a look at some pros and cons of eating only animal products.
PRO: Elimination of Some Inflammatory Foods
There is some benefit in the short term use of a carnivore diet if it is used as an elimination diet.
A diet that avoids all plant-based foods would naturally contain no gluten or sugar, which are inflammatory foods that can cause digestive problems.
By going all-meat for a short period, and then slowly adding healthy carbs back into their diet, a person could theoretically pinpoint irritating foods to avoid long-term.
A carnivore diet would also naturally eliminate FODMAPs. This is an acronym that describes types of carbohydrates that don’t digest easily.

PRO: Weight Loss
People find the Carnivore Diet inviting as a weight-loss tool. As long as you are not overeating protein and are avoiding carbs, your body would have a hard time maintaining insulin levels high enough to block fat burning.
The lack of variety in the diet could also lead to disinterest in eating. This could have an unintentional calorie restriction effect that adds to weight loss.
PRO: Quicken Ketosis
The carnivore diet would push your body into ketosis fairly quickly because the lack of carbs would force your body to make ketones.
CON: Lack of Variety
The carnivore diet has a lack of variety. For some, this would be a non-issue, but a carnivore diet would completely eliminate nuts, seeds, berries, and vegetables that keep a diet interesting and enjoyable.
CON: Lack of Research
There is a lack of research into the long-term effects of the diet. This does not mean that the diet will inevitably be found to be dangerous, but at this point, the consequences are not known.
Until more research is available, there is no certainty that life on animal products alone is beneficial or dangerous.
CON: Impact on Gut Health?
One thing that is lacking from this diet is fiber. Fiber is a non-digestible carbohydrate that can be used as food by the good bacteria in your gut.
Fiber leads to the creation of short-chain fatty acids that are produced when the good gut bacteria ferment fiber in your colon.
These unique molecules have a tremendous anti-inflammatory effect on your body, which is vital for the prevention of many diseases. They also specifically benefit the health of your colon.
If colorectal cancer is something that runs in your family, you might want to look twice before cutting out all vegetables and whole carbs.

CON: Possible Nutrient Deficiencies
There are nutrients that we cannot easily get from animal products alone.
- Fiber is one of those nutrients. Beyond being food for your friendly gut bacteria, fiber promotes healthy bowel movements. This means that constipation can be an issue with the carnivore diet.
- Vitamin C is another nutrient that is most abundant in plant foods. Your body cannot make or store vitamin C so it must come from your diet.
- Phytonutrients, which are literally plant nutrients, would be lacking in the diet. These nutrients only come from plant foods and act as antioxidants that protect your cells from damage. They have been shown to reduce the risk of serious conditions like cancer, heart disease, stroke, and Alzheimer’s.

Bottom Line on The Carnivore Diet
I see the appeal of the carnivore diet for some individuals. However, I question if it is necessary to go to the extreme of eliminating all carbs for three main reasons.
- First, there is a nutritional value obtained from eating a mix of plant and animal foods.
- Second, we still have a lot to learn about the impact an all-meat diet has on your overall health.
- And lastly, even the most stubborn metabolisms can be coaxed to burn fat by simply limiting carbs rather than omitting them.
About the Author
Dr. Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.