https://youtu.be/150aE6oXadc

The Carnivore Diet At-A-Glance:

Pros:

• Potentially positive change in metabolism due to change in protein/carb/fat intakes
• Weight management opportunity
• Beneficial for diet-based diabetes management
• Reset use of fat as fuel for our bodies in a world addicted to sugar

Cons:

• Highly restrictive, extremely difficult to maintain
• Lack of dietary fiber
• Higher potential risk of cardiovascular disease
• Increased risk of certain cancers
• Not intended for long-term practice; no long-term studies to prove its safety

Ayurvedic Perspective:

• Meat-based diet is perfectly appropriate for winter/spring, but illogical and potentially harmful year-round
• Diet should change with seasonal harvest and microbiome
• Fat-burning reset diets (like carnivore and keto diets) are most effective in spring
• No extreme and restrictive diet is ideal for year-round use or long-term health
• Ketosis is beneficial in the short term, unless you have evolutionary advantages like the Inuits for long-term use

Can Our Bodies Handle Long-Term Ketosis?

Entirely animal-based diets are not new. The Inuits of the Arctic Circle have a naturally occurring high protein and high fat diet. In the 1920’s, explorers participated in a study that mimicked the indigenous “carnivore” diet of the Inuits, and after one year on the diet they were experiencing good health and longevity. Dr. John Rollo in 1797 may have been the first to study the effects of a no-carbohydrate diet (all meat) on type 2 diabetics in St. Lucia. The results were so successful, this version of a carnivore diet became a standard of care for diabetes in the 19th century, until insulin was discovered and quickly replaced dietary treatment for the treatment of type 2 diabetes. These studies also demonstrated significant improvement in metabolic health, including lower lipid and cholesterol levels. 

In a 2021 study, over 2,000 folks followed a carnivore diet for up to 20 months. Of these 2,000 people, 262 of them had either type 1 or 2 diabetes. The participants with type 2 diabetes saw lower levels of HB A1C and long term measures of blood sugar, along with reductions in the use of blood sugar medications. Of the 262 participants with diabetes, 84% of them were able to discontinue their oral medications. Of those with just type 2 diabetes, 92% of them discontinued their insulin! Perhaps due to the combination of no carbs and no processed food, there was also a significant reduction in weight reported in this study as well.

Does this mean we should be eating a carnivore diet on a long term timeline (like the Inuits)? Not so fast. When westerners ate a traditional Inuit diet, they quickly built up ketones in the blood and urine while the Inuits did not. We still do not know the long-term health impact of eating a carnivore diet for an extended time.

The Inuits have evolved to have a genetic mutation that allows them to eat a high-protein, high-fat diet without going into ketogenesis. This suggests that evolution protected them from possible long term side effects and risks of ketogenesis. For westerners, the secret to any success with this diet may be a matter of dose and duration.

What is the Carnivore Diet?

A true Carnivore Diet (as prescribed by Dr. Shawn Baker, M.D., author of The Carnivore Diet) eliminates plant-based foods like fruits, vegetables, grains, beans, nuts, and seeds. It is a 100% animal-based product diet that emphasizes meat, poultry, fish, organ meats, eggs and full fat dairy. Tea and coffee are considered OK. Some versions of the diet allow low carb plant-based foods like greens, zucchini, broccoli, and spinach, along with low carb berries, nuts, and seeds. Here is what you might eat on a typical day eating a carnivore diet:

• Breakfast: Eggs and bacon
• Lunch: Hamburger patties with cheese
• Snack: Sardines
• Dinner: Steak

As with most highly restrictive diets, knock-off diets that are easier to follow often appear claiming the same benefits. In the case of new knock-off “carnivore diets”, low-carb fruits, veggies, oils, nuts and seeds are becoming more accepted.

 Let’s turn to an academic review of the research on long-term effects of a keto diet, which is notoriously hard to follow properly. While short-term results are impressive, in the long term those on keto seem to fare about as well as those who are on less-restrictive weight loss diets.  This report suggests that (like all extreme diets, including veganism) carnivore, keto, and paleo diets are decidedly hard to stick with long term. 

The Risks of “All Meat, No Plants”

Like most restrictive diets, there seems to always be a “feel good” effect from eliminating a certain food or food group from the diet. Initially, when you restrict protein, fat, or carbs, you will see an initial change in weight, energy, mood, or metabolism…but will it last, and are there any risks? 

In the case of a carnivore diet, it is hard to ignore the decades of studies suggesting health risks among those consuming the most red meat (the holy grail of the carnivore diet). In a 2021 study with over 180,000 participants, those with the highest consumption of red meat saw a 20% increased risk of cardiovascular disease, a 53% increase in heart disease, and a 101% increased risk in dying from a stroke compared to those who consumed the least amount of meat. The study also reported that a decrease in red meat (combined with an increase of poultry and grains) was associated with a 9-16% lower risk of dying from stroke, cardiovascular issue, or heart disease.

The other risk of a carnivore diet is the lack of dietary fiber from restricting vegetables, grains and fruits. This lack of fiber is also linked to increased risk of certain cancers and heart disease. 

See also Vegan vs. Keto vs. Ayurvedic Diets: Pros and Cons 

Studies also have linked higher consumption of red and processed meat to an increased risk of a variety of cancers including breast and colorectal cancer that make staying on a carnivore diet a valid concern.  That said, emerging studies are showing that grass-fed beef is associated with a lower risk of some cancers and cardiovascular disease. So, if you choose to give a carnivore diet a go, I would suggest to do it only for a month in the spring. I highly recommend that the animal products be of the highest quality as well (organic and grass-fed).

The Ayurvedic + Seasonal Context

As I mentioned earlier, the answer as to whether a carnivore diet is healthy may be a matter of dose and duration. In nature, the nutritional cycle is an annual one. Each season offers a surge in one of the macronutrients. In the summer through fall, nature provides a carbohydrate-rich harvest, with lots of fruits and vegetables. In the late fall through winter, we see higher protein and higher fat levels in the harvest of nuts, seeds, and grains. As winter progresses, food stores dwindle. Our ancestors were forced to hunt and thus increase their intake of fat and protein. Come early spring, there are no carbs to harvest… so the gut microbiome shifts to proliferate a strain of bacteria called actinobacteria which are better at delivering fat as a source of fuel. The fuel supply changes once again in the late summer/fall. The gut bugs shift to a predominance of bacteroidetes which  are proficient in delivering carbs and glucose into the bloodstream.  This is our body’s response to the changing fuel supply from fat back to fruit, starch, and sugar in late summer. Come spring the cycle starts again.

See also 4-Step Prebiotic and Probiotic Protocol for a Healthy Microbiome

Eating a carnivore diet in the summer when nature is exploding with fruits, roots, nuts, seeds, veggies, and grains is illogical. 

Why over-hunt in the summer and risk starvation come winter when you cannot consume the summer vegetables from your garden fast enough?  In nature, the amount of protein consumed would increase in the winter-to- spring period. After a long winter, in early spring our ancestors would eat a low-carb or no-carb diet that was supplemented with animal protein.We would go into a natural state of caloric restriction, which is interestingly linked to the timing of the many religious fasts in springtime.

So according to the studies and feedback on the carnivore diet, it falls into the category of an extreme and possiblymedicinal diet that can break the microbial addiction to sugar. Fully restricting carbohydrates, which happens every spring if living off the land, will force the body to burn fat as fuel and reset our ability to handle sugar come fall without the risk of hyperglycemia or the inability to handle sugar. 

In my opinion, based on the research I have done, the carnivore diet is not meant to be a life-long diet. In a culture where prediabetes and diabetes are an epidemic, it is understandable why the keto, paleo, and carnivore diets have gained traction; they break our metabolic addiction to sugar and reset our ability to burn fat (which is a more stable fuel supply). If you choose a diet to reset fat metabolism, it is most effective to do it in the spring, when the body is inclined to use fat as fuel. If we would adhere to a diet that is more aligned with the changing harvests (i.e. avoiding carbs and calorie restricting each spring) such extreme diets like the carnivore diet would not be necessary.

How Do I Begin Eating Seasonally?

I compiled a guide to seasonal eating and the science behind it in my book,  The 3-Season Diet.  It is based on the 3 primary harvests: a spring harvest, summer harvest, and a fall harvest which extends during the mostly dormant winter months.

We publish a free seasonal eating guide called The 3-Season Diet Guide.  This monthly email-based guide will deliver grocery lists, superfoods, herbs and strategies to navigate the changing of each season.